Multichannel test circuit and method for MLCC capacitor

Abstract

The invention discloses a multi-channel test circuit and method for MLCC capacitors. The circuit comprises a control unit MCU, a capacitor, a switching module, a plurality of clamping protection circuits and a plurality of tested MLCC capacitors. Wherein the input end of the switching module is electrically connected with a tested MLCC capacitor; the control unit is electrically connected with the control end of the switching module, and the control unit is also used for being electrically connected with an upper computer; the capacitance meter is electrically connected with the control unit and is also electrically connected with the output end of the switching module; one end of the clamping protection circuit is electrically connected with the input end of the switching module, and the other end of the clamping protection circuit is electrically connected with the capacitance meter. The capacitance meter can be protected from being burnt by residual high voltage of the capacitor, one or two capacitance meters can be tested in a multi-channel mode, the structure is simple, control is easy, the technology is simple, an electric circuit is simple and clear, testing operation is easy, interference between the capacitance meters is reduced, testing quality is improved, cost is reduced, and wide application is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic application testing, and in particular to a multi-channel testing circuit and method for MLCC capacitors. Background Art

[0002] In related technologies, MLCC (Multi-layer Ceramic Capacitors) is the abbreviation of chip-type multilayer ceramic capacitors. It is made by stacking ceramic dielectric diaphragms with printed electrodes (inner electrodes) in a staggered manner, sintering at high temperature once to form a ceramic chip, and then sealing the two ends of the chip with metal layers (outer electrodes), thus forming a structure similar to a monolith, so it is also called a monolithic capacitor.

[0003] MLCC capacitors are widely used and have become the main force in the electronics field. The terminal market of MLCC capacitor devices mainly covers smart phones, audio and video equipment, computers, automobiles, other industries, medical and various home appliances. The demand for MLCC capacitors is gradually increasing, the daily output is very amazing, the quality requirements are becoming more and more stringent, and the requirements for capacitor testing are also getting higher and higher; whether there are defective MLCC capacitors, how is the reliability, capacitance and dielectric loss factor (DF, Dissipation Factor) and other series of problems.

[0004] In the field of MLCC testing, the existing technical solution for multi-channel testers is to install a capacitance meter on each track for the corresponding test. For example, for 8-channel measurement, 8 capacitance meters are needed, which leads to a sharp increase in the number of capacitance meters used in the tester. In addition, the capacitance meters are expensive, with more control interfaces, complex processes, and numerous components. The MLCC capacitors being tested may have residual high voltage. If they are directly connected to the capacitance meter without a discharge circuit, there is a risk of burning the capacitance meter. It cannot meet the needs of various customers and is difficult to be widely used. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a multi-channel test circuit for MLCC capacitors, which can protect the capacitance meter from being burned by residual high voltage in the tested MLCC capacitors, and can realize multi-channel testing corresponding to one or two capacitance meters, with a simple structure, few control interfaces, simple process, reduced interference between capacitance meters, improved test quality, greatly reduced various costs, and meet various test needs of customers, and is convenient for wide application.

[0006] The present invention also provides a multi-channel testing method for MLCC capacitors using the multi-channel testing circuit for the MLCC capacitors.

[0007] A multi-channel test circuit for an MLCC capacitor according to a first aspect of the present invention includes: Several MLCC capacitors under test; A switching module, wherein an input end of the switching module is electrically connected to the MLCC capacitor under test; A control unit, the control unit is electrically connected to the control end of the switching module, and the control unit is also used to be electrically connected to a host computer; A plurality of capacitance meters, wherein the capacitance meters are electrically connected to the control unit and are also electrically connected to the output end of the switching module; A plurality of clamping protection circuits, one end of each clamping protection circuit is electrically connected to the input end of the switching module, and the other end of each clamping protection circuit is electrically connected to the capacitance meter.

[0008] According to some embodiments of the present invention, the switching module includes a plurality of switching units, and the switching units are divided into an H-end switching unit and an L-end switching unit, and the H-end switching unit corresponds to the L-end switching unit one by one; The H-end switching units correspond to the MLCC capacitors under test one by one, the input ends of the H-end switching units are electrically connected to the high level ends of the corresponding MLCC capacitors under test, and the output ends of the H-end switching units are electrically connected to the capacitance meter; The L-end switching unit corresponds one-to-one to the MLCC capacitor under test, the input end of the L-end switching unit is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and the output end of the L-end switching unit is electrically connected to the capacitance meter.

[0009] According to some embodiments of the present invention, the clamping protection circuit includes: a clamping protection TVS diode, the clamping protection TVS diode corresponds to the switching unit one by one, one end of the clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the clamping protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; The H-end switching unit comprises: A first H-terminal switching switch, wherein an input end of the first H-terminal switching switch is electrically connected to a high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; an output end of the first H-terminal switching switch is electrically connected to a protection terminal (GUARD) of the capacitance meter; A second H-end switching switch, wherein the input end of the second H-end switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second H-end switching switch is electrically connected to the high voltage terminal (HPOT) of the capacitance meter through a first shielding net; A third H-terminal switching switch, wherein the input end of the third H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third H-terminal switching switch is electrically connected to the high current terminal (HCUR) of the capacitance meter through a second shielding net.

[0010] According to some embodiments of the present invention, the L-terminal switching unit includes: A first L-terminal switching switch, wherein an input end of the first L-terminal switching switch is electrically connected to a low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; an output end of the first L-terminal switching switch is electrically connected to a protection terminal (GUARD) of the capacitance meter; A second L-terminal switching switch, wherein the input end of the second L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second L-terminal switching switch is electrically connected to the low voltage terminal (LPOT) of the capacitance meter through a third shielding net; A third L-terminal switching switch, wherein the input end of the third L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third L-terminal switching switch is electrically connected to the low current terminal (LCUR) of the capacitance meter through a fourth shielding net.

[0011] According to some embodiments of the present invention, the clamping protection circuit includes: a first clamping protection TVS diode and a second clamping protection TVS diode, the first clamping protection TVS diode and the second clamping protection TVS diode both correspond to the switching unit one by one; one end of the first clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the first clamping protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; one end of the second clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the second clamping protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; The H-end switching unit comprises: A fourth H-terminal switching switch, wherein the input end of the fourth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through a fifth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth H-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A fifth H-terminal switching switch, wherein the input end of the fifth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through a sixth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth H-terminal switching switch is electrically connected to the high voltage terminal (HPOT) of the capacitance meter through a seventh shielding net; A sixth H-terminal switching switch, wherein the input end of the sixth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through an eighth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth H-terminal switching switch is electrically connected to the high current terminal (HCUR) of the capacitance meter through a ninth shielding net; A seventh H-terminal switching switch, wherein the input end of the seventh H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through the tenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh H-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter.

[0012] According to some embodiments of the present invention, the L-terminal switching unit includes: A fourth L-terminal switching switch, wherein the input end of the fourth L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through an eleventh shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth L-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A fifth L-end switching switch, wherein the input end of the fifth L-end switching switch is electrically connected to the low level end of the corresponding MLCC capacitor under test through a twelfth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth L-end switching switch is electrically connected to the low voltage terminal (LPOT) of the capacitance meter through a thirteenth shielding net; A sixth L-terminal switching switch, wherein the input end of the sixth L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through a fourteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth L-terminal switching switch is electrically connected to the low current terminal (LCUR) of the capacitance meter through a fifteenth shielding net; A seventh L-terminal switching switch, wherein the input end of the seventh L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through a sixteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh L-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter.

[0013] According to some embodiments of the present invention, the switching unit further includes: A first drive circuit, wherein one end of the first drive circuit is electrically connected to the control unit, and the other end of the first drive circuit is electrically connected to the control end of the third H-end switch or the third L-end switch; the other end of the first drive circuit is also electrically connected to the control end of the second H-end switch or the second L-end switch; A first reverse circuit, one end of the first reverse circuit is electrically connected to the other end of the first drive circuit, and the other end of the first reverse circuit is electrically connected to the control end of the third H-end switching switch or the third L-end switching switch.

[0014] According to some embodiments of the present invention, the switching unit further includes: A second drive circuit, wherein one end of the second drive circuit is electrically connected to the control unit, and the other end of the second drive circuit is electrically connected to the control end of the fifth H-end switch or the fifth L-end switch; the other end of the second drive circuit is also electrically connected to the control end of the sixth H-end switch or the sixth L-end switch; A second reverse circuit, one end of the second reverse circuit is electrically connected to the other end of the second drive circuit, and the other end of the second reverse circuit is electrically connected to the control end of the fourth H-end switching switch or the fourth L-end switching switch; the other end of the second reverse circuit is also electrically connected to the control end of the seventh H-end switching switch or the seventh L-end switching switch.

[0015] A multi-channel testing method for an MLCC capacitor according to an embodiment of the second aspect of the present invention includes: When the host computer does not output a trigger signal to the control unit, the control unit outputs a first control signal to the switching module, and the switching module connects the MLCC capacitor under test to the clamping protection circuit; When the host computer outputs a trigger signal to the control unit, the control unit determines that the test is allowed to start; When the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal, and performs the test; When the MLCC capacitors under test in all channels are tested, the control unit changes the level of the trigger signal to indicate that the test is completed.

[0016] According to some embodiments of the present invention, when the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal, and performs the test, including: When the test starts, the control unit outputs a high-level control signal to the corresponding switching unit according to the preset timing, and the corresponding switching unit connects the corresponding MLCC capacitor under test to the capacitance meter and disconnects the corresponding clamping protection circuit to perform a capacitance parameter test of the corresponding MLCC capacitor under test; When the corresponding MLCC capacitor under test completes the test, the control unit outputs a low-level control signal to the corresponding switching unit, and the corresponding switching unit disconnects the corresponding MLCC capacitor under test from the capacitance meter and connects with the corresponding clamping protection circuit to form a discharge loop.

[0017] The multi-channel test circuit and method of the MLCC capacitor according to the embodiment of the present invention have at least the following beneficial effects: by connecting the input end of the switching module in parallel with one end of the clamping protection circuit, and electrically connecting them to the MLCC capacitor under test, while the output end of the switching module and the other end of the clamping protection circuit are electrically connected to the capacitance meter, and the control end is electrically connected to the control module, and before or after the measurement, the control unit controls the switching module so that the MLCC capacitor under test is connected to the clamping protection circuit to form a discharge circuit, thereby avoiding the capacitance meter from being burned by the residual high voltage existing in the MLCC capacitor under test during the test, and can achieve the test of MLCC capacitors of multiple channels corresponding to one or two capacitance meters, with a simple overall structure, simple control requirements, and simple process. The lines between the capacitance transformer and the MLCC capacitor under test on each channel are simple and clear, the test operation is simple, and the interference between the capacitance meters is reduced, the test quality is improved, various costs are greatly reduced, and various different test requirements are met, which facilitates the wide application of the circuit.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 A schematic diagram of the process steps of a multi-channel testing method for MLCC capacitors according to an embodiment of the present invention; Figure 2 1 is a circuit structure block diagram of a multi-channel test circuit for an MLCC capacitor according to an embodiment of the present invention; Figure 3 for Figure 2 A topological diagram of a first capacitance meter showing a first connection mode of a switching module of a multi-channel test circuit for MLCC capacitors; Figure 4 for Figure 2 A topological diagram of a second capacitance meter showing a first connection mode of a switching module of a multi-channel test circuit for MLCC capacitors; Figure 5 for Figure 2 A topological diagram of a first capacitance meter showing a second connection mode of a switching module of a multi-channel test circuit for MLCC capacitors; Figure 6 for Figure 2 A topological diagram of a second capacitance meter showing a second connection mode of a switching module of a multi-channel test circuit for MLCC capacitors; Figure 7 for Figure 2 A topological structure diagram of a third connection mode of a switching module of a multi-channel test circuit for MLCC capacitors is shown; Figure 8 for Figure 2 A topological structure diagram of a fourth connection mode of a switching module of a multi-channel test circuit for MLCC capacitors is shown; Fig. 9 for Figure 3 or Figure 7 An electrical schematic diagram of a first circuit form of a switching unit of a switching module of a multi-channel test circuit showing a first or third connection mode of an MLCC capacitor; Fig.10 for Figure 3 or Figure 7 An electrical schematic diagram of a second circuit form of a switching unit of a switching module of a multi-channel test circuit showing the first or third connection mode of an MLCC capacitor; Fig.11 for Figure 3 or Figure 7 An electrical schematic diagram of a third circuit form of a switching unit of a switching module of a multi-channel test circuit showing the first or third connection mode of an MLCC capacitor; Fig.12 for Figure 5 or Figure 8 An electrical schematic diagram of a first circuit form of a switching unit of a switching module of a multi-channel test circuit showing a second or fourth connection mode of an MLCC capacitor; Fig.13 for Figure 5 or Figure 8An electrical schematic diagram of a second circuit form of a switching unit of a switching module of a multi-channel test circuit showing a second or fourth connection mode of an MLCC capacitor; Fig.14 for Figure 5 or Figure 8 An electrical schematic diagram of a third circuit form of a switching unit of a switching module of a multi-channel test circuit showing the second or fourth connection mode of an MLCC capacitor; Fig.15 for Figure 3 The schematic diagram of the waveforms of various electrical signals when the switching module of the multi-channel test circuit of the MLCC capacitor is connected in the first manner; Fig.16 for Figure 5 The schematic diagram of the waveforms of various electrical signals when the switching module of the multi-channel test circuit of the MLCC capacitor is connected in the second way; Fig.17 for Figure 7 The schematic diagram of the waveforms of various electrical signals when the switching module of the multi-channel test circuit of the MLCC capacitor is connected in the third way is shown; Fig.18 for Figure 8 A schematic diagram showing waveforms of various electrical signals when the switching module of the multi-channel test circuit of the MLCC capacitor is connected in the fourth manner. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the circuits or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0022] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0024] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0025] Reference Figure 2 The present invention proposes a multi-channel test circuit for MLCC capacitors, comprising: Several MLCC capacitors under test; A switching module, wherein an input terminal of the switching module is electrically connected to the MLCC capacitor under test; A control unit, the control unit is electrically connected to the control end of the switching module, and the control unit is also used to be electrically connected to a host computer; A plurality of capacitance meters, the capacitance meters are electrically connected to the control unit, and the capacitance meters are also electrically connected to the output end of the switching module; A plurality of clamping protection circuits, one end of the clamping protection circuit is electrically connected to the input end of the switching module, and the other end of the clamping protection circuit is electrically connected to the capacitance meter.

[0026] Specifically, in this embodiment, the multi-channel test circuit of the MLCC capacitor includes a control unit MCU, a capacitor meter 1, a capacitor meter 2 (or only a capacitor meter 1), a switching module, a clamping protection circuit and 8 channels of tested MLCC capacitors; It should be noted that the control unit includes a single chip microcomputer, a PLC, an FPGA, etc.

[0027] Capacitor Table 1 and Capacitor Table 2 are used to measure the capacitance and dielectric loss factor (DF) of MLCC capacitors; The switching module includes an H-end CH1 to CH4 switching module, an H-end CH5 to CH8 switching module, an L-end CH1 to CH4 switching module and an L-end CH5 to CH8 switching module, which are used to switch the corresponding channels for the capacitance meter to measure the MLCC capacitance value and dielectric loss factor (DF); The H-end CH1 to CH4 switching module includes a switching unit HCH1, a switching unit HCH2, a switching unit HCH3 and a switching unit HCH4; The H-end CH5 to CH8 switching module includes a switching unit HCH5, a switching unit HCH6, a switching unit HCH7 and a switching unit HCH8; The L-end CH1 to CH4 switching module includes a switching unit LCH1, a switching unit LCH2, a switching unit LCH3 and a switching unit LCH4; The L-end CH5 to CH8 switching module includes a switching unit LCH5, a switching unit LCH6, a switching unit LCH7 and a switching unit LCH8; The clamping protection circuit is used to prevent the residual voltage of the MLCC capacitor under test from being too large, thereby burning the measurement circuit and capacitance meter, causing harm and loss; Capacitance meter 1 and capacitance meter 2 are connected to the control unit MCU through a communication interface and a hardware IO interface; The communication interface includes serial port, RS485 interface, GPIB interface, USB interface, SPI interface, I2C interface, parallel interface, Ethernet interface, hardware IO interface, etc., which are used to transmit information between the capacitance meter and the control unit MCU. The switching module is installed between the capacitance meter and the MLCC capacitor to be tested.

[0028] By using a fast detection and sorting switching circuit module (i.e., switching module), the number of capacitance meters used is reduced, making the multi-channel tester simple in structure, simple in control, simple in process, and simple in various test operations; the switching circuit of the fast detection and sorting switching circuit module can switch the MLCC capacitor under test to form a discharge circuit, thereby avoiding residual high voltage in the MLCC capacitor under test from burning the capacitance meter; using the installation position of the fast detection and sorting switching circuit module, customers can choose a suitable switching circuit mode module according to the structural layout of the tester to improve the efficiency and quality of MLCC capacitor testing; using the fast detection and sorting switching circuit module, the interference between various capacitance meters is reduced, the test quality is improved, and various costs are reduced, which is more suitable for the testing needs of multi-channel automated rapid screening testers on the production line and meets various testing needs of customers.

[0029] Reference Figure 2 ,Further, in some embodiments of the present invention, the switching module includes a plurality of switching units, the switching units are divided into H-end switching units and L-end switching units, and the H-end switching units correspond to the L-end switching units one by one; The H-end switching units correspond to the MLCC capacitors under test one by one, the input ends of the H-end switching units are electrically connected to the high-level ends of the corresponding MLCC capacitors under test, and the output ends of the H-end switching units are electrically connected to the capacitance meter; The L-end switching units correspond one-to-one to the MLCC capacitors under test, the input ends of the L-end switching units are electrically connected to the low-level ends of the corresponding MLCC capacitors under test, and the output ends of the L-end switching units are electrically connected to the capacitance meter.

[0030] Specifically, in this embodiment, the switching module includes an H-end CH1 to CH4 switching module, an H-end CH5 to CH8 switching module, an L-end CH1 to CH4 switching module, and an L-end CH5 to CH8 switching module, which are used to switch the corresponding channels for the capacitance meter to measure the MLCC capacitance value and dielectric loss factor (DF); The H-end CH1 to CH4 switching module includes a switching unit HCH1, a switching unit HCH2, a switching unit HCH3 and a switching unit HCH4; The H-end CH5 to CH8 switching module includes a switching unit HCH5, a switching unit HCH6, a switching unit HCH7 and a switching unit HCH8; The L-end CH1 to CH4 switching module includes a switching unit LCH1, a switching unit LCH2, a switching unit LCH3 and a switching unit LCH4; The L-end CH5 to CH8 switching module includes a switching unit LCH5 , a switching unit LCH6 , a switching unit LCH7 and a switching unit LCH8 .

[0031] Reference Figure 3 and Figure 4 , further, in some embodiments of the present invention, the clamp protection circuit includes: a clamp protection TVS diode, the clamp protection TVS diode corresponds to the switching unit one by one, one end of the clamp protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the clamp protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; The H-side switching unit includes: A first H-terminal switching switch, wherein the input end of the first H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the first H-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A second H-terminal switching switch, wherein the input end of the second H-terminal switching switch is electrically connected to the high-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second H-terminal switching switch is electrically connected to the high voltage terminal (HPOT) of the capacitance meter through the first shielding net; A third H-terminal switching switch, the input end of the third H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third H-terminal switching switch is electrically connected to the high current terminal (HCUR) of the capacitance meter through the second shielding net.

[0032] Reference Figure 3 and Figure 4 , further, in some embodiments of the present invention, the L-end switching unit includes: A first L-terminal switching switch, wherein the input end of the first L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the first L-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A second L-end switching switch, wherein the input end of the second L-end switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second L-end switching switch is electrically connected to the low voltage terminal (LPOT) of the capacitance meter through a third shielding net; A third L-terminal switching switch, the input end of the third L-terminal switching switch is electrically connected to the low level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third L-terminal switching switch is electrically connected to the low current terminal (LCUR) of the capacitance meter through a fourth shielding net.

[0033] Specifically, in the above two embodiments, Figure 3 and Figure 4 The first switching circuit form shown is a switching circuit mode, a switching unit HCH1: one end of SW1 is connected to Hch1, and the other end is connected to a capacitance meter, Guard#1; one end of SW2 is connected to Hch1, and the other end is connected to a capacitance meter, Hpot#1; one end of SW3 is connected to Hch1, and the other end is connected to a capacitance meter, Hcur#1; one end of a clamping TVS diode D1 in a clamping protection circuit is connected to Hch1, and the other end is connected to a capacitance meter, Guard#1; Switching circuit mode - switching unit LCH1: one end of SW13 is connected to Lch1, and the other end is connected to a capacitance meter - Guard#1; one end of SW14 is connected to Lch1, and the other end is connected to a capacitance meter - Lpot#1; one end of SW15 is connected to Lch1, and the other end is connected to a capacitance meter - Lcur#1; one end of the clamping TVS diode D5 in the clamping protection circuit is connected to Lch1, and the other end is connected to a capacitance meter - Guard#1; One end of the MLCC capacitor C1 under test in CH1 is connected to Hch1, and the other end is connected to Lch1.

[0034] Switching circuit mode - switching unit HCH2: one end of SW4 is connected to Hch2, and the other end is connected to a capacitance meter - Guard#1; one end of SW5 is connected to Hch2, and the other end is connected to a capacitance meter - Hpot#1; one end of SW6 is connected to Hch2, and the other end is connected to a capacitance meter - Hcur#1; one end of the clamping TVS diode D2 in the clamping protection circuit is connected to Hch2, and the other end is connected to a capacitance meter - Guard#1; Switching circuit mode - switching unit LCH2: one end of SW16 is connected to Lch2, and the other end is connected to a capacitance meter - Guard#1; one end of SW17 is connected to Lch2, and the other end is connected to a capacitance meter - Lpot#1; one end of SW18 is connected to Lch2, and the other end is connected to a capacitance meter - Lcur#1; one end of the clamping TVS diode D6 in the clamping protection circuit is connected to Lch2, and the other end is connected to a capacitance meter - Guard#1; One end of the MLCC capacitor C2 under test in CH2 is connected to Hch2, and the other end is connected to Lch2.

[0035] Switching circuit mode - switching unit HCH3: one end of SW7 is connected to Hch3, and the other end is connected to a capacitance meter - Guard#1; one end of SW8 is connected to Hch3, and the other end is connected to a capacitance meter - Hpot#1; one end of SW9 is connected to Hch3, and the other end is connected to a capacitance meter - Hcur#1; one end of the clamping TVS diode D3 in the clamping protection circuit is connected to Hch3, and the other end is connected to a capacitance meter - Guard#1; Switching circuit mode - switching unit LCH3: one end of SW19 is connected to Lch3, and the other end is connected to a capacitance meter - Guard#1; one end of SW20 is connected to Lch3, and the other end is connected to a capacitance meter - Lpot#1; one end of SW21 is connected to Lch3, and the other end is connected to a capacitance meter - Lcur#1; one end of the clamping TVS diode D7 in the clamping protection circuit is connected to Lch3, and the other end is connected to a capacitance meter - Guard#1; One end of the MLCC capacitor under test CH3 is connected to Hch3, and the other end is connected to Lch3.

[0036] Switching circuit mode - switching unit HCH4: one end of SW10 is connected to Hch4, and the other end is connected to a capacitance meter - Guard#1; one end of SW11 is connected to Hch4, and the other end is connected to a capacitance meter - Hpot#1; one end of SW12 is connected to Hch4, and the other end is connected to a capacitance meter - Hcur#1; one end of the clamping TVS diode D4 in the clamping protection circuit is connected to Hch4, and the other end is connected to a capacitance meter - Guard#1; Switching circuit mode - switching unit LCH4: one end of SW22 is connected to Lch4, and the other end is connected to a capacitance meter - Guard#1; one end of SW23 is connected to Lch4, and the other end is connected to a capacitance meter - Lpot#1; one end of SW24 is connected to Lch4, and the other end is connected to a capacitance meter - Lcur#1; one end of the clamping TVS diode D8 in the clamping protection circuit is connected to Lch4, and the other end is connected to a capacitance meter - Guard#1; One end of the MLCC capacitor under test, CH4, is connected to Hch4, and the other end is connected to Lch4.

[0037] In switching circuit mode 1, a coaxial shielded cable is used between the Hcur#1 and Hpot#1 signals of the capacitance meter 1 and the H-end CH1 to CH4 switching module, and its shielding net is connected to the capacitance meter 1 Guard#1; in switching circuit mode 1, a coaxial shielded cable is used between the Lcur#1 and Lpot#1 signals of the capacitance meter 1 and the L-end CH1 to CH4 switching module, and its shielding net is connected to the capacitance meter 1 Guard#1.

[0038] Switching circuit mode 1: Switching unit HCH5: one end of SW25 is connected to Hch5, and the other end is connected to the second capacitance meter Guard#2; one end of SW26 is connected to Hch5, and the other end is connected to the second capacitance meter Hpot#2; one end of SW27 is connected to Hch5, and the other end is connected to the second capacitance meter Hcur#2; one end of the clamping TVS diode D9 in the clamping protection circuit is connected to Hch5, and the other end is connected to the second capacitance meter Guard#2; Switching circuit mode 1: Switching unit LCH5: one end of SW37 is connected to Lch5, and the other end is connected to the second capacitance meter Guard#2; one end of SW38 is connected to Lch5, and the other end is connected to the second capacitance meter Lpot#2; one end of SW39 is connected to Lch5, and the other end is connected to the second capacitance meter Lcur#2; one end of the clamping TVS diode D13 in the clamping protection circuit is connected to Lch5, and the other end is connected to the second capacitance meter Guard#2; One end of the MLCC capacitor C5 under test in CH5 is connected to Hch5, and the other end is connected to Lch5.

[0039] Switching circuit mode 1: Switching unit HCH6: one end of SW28 is connected to Hch6, and the other end is connected to the second capacitance meter Guard#2; one end of SW29 is connected to Hch6, and the other end is connected to the second capacitance meter Hpot#2; one end of SW30 is connected to Hch6, and the other end is connected to the second capacitance meter Hcur#2; one end of the clamping TVS diode D10 in the clamping protection circuit is connected to Hch6, and the other end is connected to the second capacitance meter Guard#2; Switching circuit mode 1: Switching unit LCH6: one end of SW40 is connected to Lch6, and the other end is connected to the second capacitance meter Guard#2; one end of SW41 is connected to Lch6, and the other end is connected to the second capacitance meter Lpot#2; one end of SW42 is connected to Lch6, and the other end is connected to the second capacitance meter Lcur#2; one end of the clamping TVS diode D14 in the clamping protection circuit is connected to Lch6, and the other end is connected to the second capacitance meter Guard#2; One end of the MLCC capacitor C6 under test in CH6 is connected to Hch6, and the other end is connected to Lch6.

[0040] Switching circuit mode 1: Switching unit HCH7: one end of SW31 is connected to Hch7, and the other end is connected to the second capacitance meter Guard#2; one end of SW32 is connected to Hch7, and the other end is connected to the second capacitance meter Hpot#2; one end of SW33 is connected to Hch7, and the other end is connected to the second capacitance meter Hcur#2; one end of the clamping TVS diode D11 in the clamping protection circuit is connected to Hch7, and the other end is connected to the second capacitance meter Guard#2; Switching circuit mode 1: Switching unit LCH7: one end of SW43 is connected to Lch7, and the other end is connected to the second capacitance meter Guard#2; one end of SW44 is connected to Lch7, and the other end is connected to the second capacitance meter Lpot#2; one end of SW45 is connected to Lch7, and the other end is connected to the second capacitance meter Lcur#2; one end of the clamping TVS diode D15 in the clamping protection circuit is connected to Lch7, and the other end is connected to the second capacitance meter Guard#2; One end of the MLCC capacitor C7 under test in CH7 is connected to Hch7, and the other end is connected to Lch7.

[0041] Switching circuit mode 1: Switching unit HCH8: one end of SW34 is connected to Hch8, and the other end is connected to the second capacitance meter Guard#2; one end of SW35 is connected to Hch8, and the other end is connected to the second capacitance meter Hpot#2; one end of SW36 is connected to Hch8, and the other end is connected to the second capacitance meter Hcur#2; one end of the clamping TVS diode D12 in the clamping protection circuit is connected to Hch8, and the other end is connected to the second capacitance meter Guard#2; Switching circuit mode 1: Switching unit LCH8: one end of SW46 is connected to Lch8, and the other end is connected to the second capacitance meter Guard#2; one end of SW47 is connected to Lch8, and the other end is connected to the second capacitance meter Lpot#2; one end of SW48 is connected to Lch8, and the other end is connected to the second capacitance meter Lcur#2; one end of the clamping TVS diode D16 in the clamping protection circuit is connected to Lch8, and the other end is connected to the second capacitance meter Guard#2; One end of the MLCC capacitor C8 under test in CH8 is connected to Hch8, and the other end is connected to Lch8.

[0042] In switching circuit mode 1, a coaxial shielded cable is used between the Hcur#2 and Hpot#2 signals of capacitor meter 2 and the H-end CH5 to CH8 switching module, and its shielding net is connected to Guard#2 of capacitor meter 2; in switching circuit mode 1, a coaxial shielded cable is used between the Lcur#2 and Lpot#2 signals of capacitor meter 2 and the L-end CH5 to CH8 switching module, and its shielding net is connected to Guard#2 of capacitor meter 2.

[0043] Or use Figure 7 The third connection method shown: in order to save the cost of the capacitance meter, the MLCC capacitor fast detection sorting switching circuit method one CH1 to CH4 topology diagram is combined with the MLCC capacitor fast detection sorting switching circuit method one CH5 to CH8 topology diagram, the capacitance meter two is removed, the capacitance meter two Guard#2 signal is connected to the capacitance meter one Guard#1, the capacitance meter two Hcur#2 signal is connected to the capacitance meter one Hcur#1, the capacitance meter two Hpot#2 signal is connected to the capacitance meter one Hpot#1, the capacitance meter two Lcur#2 signal is connected to the capacitance meter one Lcur#1, the capacitance meter two Lpot#2 signal is connected to the capacitance meter one Lpot#1, thus forming the MLCC capacitor fast detection sorting switching circuit method three CH1 to CH8 topology diagram; Reference Figure 5 and Figure 6 , further, in some embodiments of the present invention, the clamping protection circuit includes: a first clamping protection TVS diode and a second clamping protection TVS diode, the first clamping protection TVS diode and the second clamping protection TVS diode both correspond to the switching units one by one; one end of the first clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the first clamping protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; one end of the second clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the second clamping protection TVS diode is electrically connected to the protection terminal (GUARD) of the capacitance meter; The H-side switching unit includes: A fourth H-terminal switching switch, wherein the input end of the fourth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through the fifth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth H-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A fifth H-terminal switching switch, the input end of the fifth H-terminal switching switch is electrically connected to the high-level end of the corresponding MLCC capacitor under test through the sixth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth H-terminal switching switch is electrically connected to the high voltage terminal (HPOT) of the capacitance meter through the seventh shielding net; A sixth H-terminal switching switch, the input end of the sixth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through the eighth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth H-terminal switching switch is electrically connected to the high current terminal (HCUR) of the capacitance meter through the ninth shielding net; The seventh H-terminal switching switch, the input end of the seventh H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through the tenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh H-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter.

[0044] Reference Figure 5 and Figure 6 , further, in some embodiments of the present invention, the L-end switching unit includes: A fourth L-terminal switching switch, wherein the input end of the fourth L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through the eleventh shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth L-terminal switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter; A fifth L-end switching switch, the input end of the fifth L-end switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through the twelfth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth L-end switching switch is electrically connected to the low voltage terminal (LPOT) of the capacitance meter through the thirteenth shielding net; A sixth L-end switching switch, the input end of the sixth L-end switching switch is electrically connected to the low level end of the corresponding MLCC capacitor under test through the fourteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth L-end switching switch is electrically connected to the low current terminal (LCUR) of the capacitance meter through the fifteenth shielding net; The seventh L-end switching switch, the input end of the seventh L-end switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through the sixteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh L-end switching switch is electrically connected to the protection terminal (GUARD) of the capacitance meter.

[0045] Specifically, in the above two embodiments, Figure 5 and Figure 6 The second connection mode shown: the MLCC capacitor fast detection and sorting switching circuit mode 2 of the present invention is a detailed description of the connection of the CH1 to CH4 topology structure diagram, as shown in FIG. Figure 5 As shown: Switching circuit mode two, switching unit HCH1: one end of SW49 is connected to Hpot1, and the other end is connected to capacitor meter Guard#1; one end of SW50 is connected to Hpot1, and the other end is connected to capacitor meter Hpot#1; one end of the clamping TVS diode D17 in the clamping protection circuit is connected to Hpot1, and the other end is connected to capacitor meter Guard#1; one end of SW51 is connected to Hcur1, and the other end is connected to capacitor meter Hcur#1; one end of SW52 is connected to Hcur1, and the other end is connected to capacitor meter Guard#1; one end of the clamping TVS diode D18 in the clamping protection circuit is connected to Hcur1, and the other end is connected to capacitor meter Guard#1; coaxial shielded cables are used between Hpot1 and Hcur1 signals to Hch1, and their shielding nets are connected to capacitor meter Guard#1.

[0046] Switching circuit mode two switching unit LCH1: one end of SW65 is connected to Lpot1, and the other end is connected to capacitor meter Guard#1; one end of SW66 is connected to Lpot1, and the other end is connected to capacitor meter Lpot#1; one end of the clamping TVS diode D25 in the clamping protection circuit is connected to Lpot1, and the other end is connected to capacitor meter Guard#1; one end of SW67 is connected to Lcur1, and the other end is connected to capacitor meter Lcur#1; one end of SW68 is connected to Lcur1, and the other end is connected to capacitor meter Guard#1; one end of the clamping TVS diode D26 in the clamping protection circuit is connected to Lcur1, and the other end is connected to capacitor meter Guard#1; coaxial shielded cables are used between Lpot1 and Lcur1 signals to Lch1 respectively, and their shielding nets are connected to capacitor meter Guard#1.

[0047] One end of the MLCC capacitor C9 under test in CH1 is connected to Hch1, and the other end is connected to Lch1.

[0048] Switching circuit mode two switching unit HCH2: one end of SW53 is connected to Hpot2, and the other end is connected to capacitor meter-Guard#1; one end of SW54 is connected to Hpot2, and the other end is connected to capacitor meter-Hpot#1; one end of the clamping TVS diode D19 in the clamping protection circuit is connected to Hpot2, and the other end is connected to capacitor meter-Guard#1; one end of SW55 is connected to Hcur2, and the other end is connected to capacitor meter-Hcur#1; one end of SW56 is connected to Hcur2, and the other end is connected to capacitor meter-Guard#1; one end of the clamping TVS diode D20 in the clamping protection circuit is connected to Hcur2, and the other end is connected to capacitor meter-Guard#1; coaxial shielded cables are used between Hpot2 and Hcur2 signals to Hch2 respectively, and their shielding nets are connected to capacitor meter-Guard#1.

[0049] Switching circuit mode two switching unit LCH2: one end of SW69 is connected to Lpot2, and the other end is connected to capacitor meter-Guard#1; one end of SW70 is connected to Lpot2, and the other end is connected to capacitor meter-Lpot#1; one end of the clamping TVS diode D27 in the clamping protection circuit is connected to Lpot2, and the other end is connected to capacitor meter-Guard#1; one end of SW71 is connected to Lcur2, and the other end is connected to capacitor meter-Lcur#1; one end of SW72 is connected to Lcur2, and the other end is connected to capacitor meter-Guard#1; one end of the clamping TVS diode D28 in the clamping protection circuit is connected to Lcur2, and the other end is connected to capacitor meter-Guard#1; coaxial shielded cables are used between Lpot2 and Lcur2 signals to Lch2 respectively, and their shielding nets are connected to capacitor meter-Guard#1.

[0050] One end of the MLCC capacitor C10 under test in CH2 is connected to Hch2, and the other end is connected to Lch2.

[0051] Switching circuit mode two, switching unit HCH3: one end of SW57 is connected to Hpot3, and the other end is connected to capacitor meter-Guard#1; one end of SW58 is connected to Hpot3, and the other end is connected to capacitor meter-Hpot#1; one end of the clamping TVS diode D21 in the clamping protection circuit is connected to Hpot3, and the other end is connected to capacitor meter-Guard#1; one end of SW59 is connected to Hcur3, and the other end is connected to capacitor meter-Hcur#1; one end of SW60 is connected to Hcur3, and the other end is connected to capacitor meter-Guard#1; one end of the clamping TVS diode D22 in the clamping protection circuit is connected to Hcur3, and the other end is connected to capacitor meter-Guard#1; coaxial shielded cables are used between Hpot3 and Hcur3 signals to Hch3 respectively, and their shielding nets are connected to capacitor meter-Guard#1.

[0052] Switching circuit mode two switching unit LCH3: one end of SW73 is connected to Lpot3, and the other end is connected to capacitor meter Guard#1; one end of SW74 is connected to Lpot3, and the other end is connected to capacitor meter Lpot#1; one end of the clamping TVS diode D29 in the clamping protection circuit is connected to Lpot3, and the other end is connected to capacitor meter Guard#1; one end of SW75 is connected to Lcur3, and the other end is connected to capacitor meter Lcur#1; one end of SW76 is connected to Lcur3, and the other end is connected to capacitor meter Guard#1; one end of the clamping TVS diode D30 in the clamping protection circuit is connected to Lcur3, and the other end is connected to capacitor meter Guard#1; coaxial shielded cables are used between Lpot3 and Lcur3 signals to Lch3 respectively, and their shielding nets are connected to capacitor meter Guard#1.

[0053] One end of the MLCC capacitor C11 under test in CH3 is connected to Hch3, and the other end is connected to Lch3.

[0054] Switching circuit mode two switching unit HCH4: one end of SW61 is connected to Hpot4, and the other end is connected to capacitor meter Guard#1; one end of SW62 is connected to Hpot4, and the other end is connected to capacitor meter Hpot#1; one end of the clamping TVS diode D23 in the clamping protection circuit is connected to Hpot4, and the other end is connected to capacitor meter Guard#1; one end of SW63 is connected to Hcur4, and the other end is connected to capacitor meter Hcur#1; one end of SW64 is connected to Hcur4, and the other end is connected to capacitor meter Guard#1; one end of the clamping TVS diode D24 in the clamping protection circuit is connected to Hcur3, and the other end is connected to capacitor meter Guard#1; coaxial shielded cables are used between Hpot4 and Hcur4 signals to Hch4 respectively, and their shielding nets are connected to capacitor meter Guard#1.

[0055] Switching circuit mode two: switching unit LCH4: one end of SW77 is connected to Lpot4, and the other end is connected to capacitor meter Guard#1; one end of SW78 is connected to Lpot4, and the other end is connected to capacitor meter Lpot#1; one end of the clamping TVS diode D31 in the clamping protection circuit is connected to Lpot4, and the other end is connected to capacitor meter Guard#1; one end of SW79 is connected to Lcur4, and the other end is connected to capacitor meter Lcur#1; one end of SW80 is connected to Lcur4, and the other end is connected to capacitor meter Guard#1; one end of the clamping TVS diode D32 in the clamping protection circuit is connected to Lcur4, and the other end is connected to capacitor meter Guard#1; coaxial shielded cables are used between Lpot4 and Lcur4 signals to Lch4 respectively, and their shielding nets are connected to capacitor meter Guard#1.

[0056] One end of the MLCC capacitor C12 under test in CH4 is connected to Hch4, and the other end is connected to Lch4.

[0057] In switching circuit mode 2, a coaxial shielded cable is used between the Hcur#1 and Hpot#1 signals of capacitor meter 1 and the H-end CH1 to CH4 switching module, and its shielding net is connected to Guard#1 of capacitor meter 1; in switching circuit mode 2, a coaxial shielded cable is used between the Lcur#1 and Lpot#1 signals of capacitor meter 1 and the L-end CH1 to CH4 switching module, and its shielding net is connected to Guard#1 of capacitor meter 1.

[0058] The MLCC capacitor fast detection and sorting switching circuit mode II of the present invention is described in detail in the topological structure diagram of CH5 to CH8, as shown in FIG. Figure 6 As shown: Switching circuit mode two switching unit HCH5: one end of SW81 is connected to Hpot5, and the other end is connected to capacitor meter 2 Guard#2; one end of SW82 is connected to Hpot5, and the other end is connected to capacitor meter 2 Hpot#2; one end of the clamping TVS diode D33 in the clamping protection circuit is connected to Hpot5, and the other end is connected to capacitor meter 2 Guard#2; one end of SW83 is connected to Hcur5, and the other end is connected to capacitor meter 2 Hcur#2; one end of SW84 is connected to Hcur5, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D34 in the clamping protection circuit is connected to Hcur5, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Hpot5 and Hcur5 signals to Hch5 respectively, and their shielding nets are connected to capacitor meter 2 Guard#2.

[0059] Switching circuit mode two switching unit LCH5: one end of SW97 is connected to Lpot5, and the other end is connected to capacitor meter 2 Guard#2; one end of SW98 is connected to Lpot5, and the other end is connected to capacitor meter 2 Lpot#2; one end of the clamping TVS diode D41 in the clamping protection circuit is connected to Lpot5, and the other end is connected to capacitor meter 2 Guard#2; one end of SW99 is connected to Lcur5, and the other end is connected to capacitor meter 2 Lcur#2; one end of SW100 is connected to Lcur5, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D42 in the clamping protection circuit is connected to Lcur5, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Lpot5 and Lcur5 signals to Lch5 respectively, and their shielding nets are connected to capacitor meter 2 Guard#1.

[0060] One end of the MLCC capacitor C13 under test in CH5 is connected to Hch5, and the other end is connected to Lch5.

[0061] Switching circuit mode two switching unit HCH6: one end of SW85 is connected to Hpot6, and the other end is connected to capacitor meter 2 Guard#2; one end of SW86 is connected to Hpot6, and the other end is connected to capacitor meter 2 Hpot#2; one end of the clamping TVS diode D35 in the clamping protection circuit is connected to Hpot6, and the other end is connected to capacitor meter 2 Guard#2; one end of SW87 is connected to Hcur6, and the other end is connected to capacitor meter 2 Hcur#2; one end of SW88 is connected to Hcur6, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D36 in the clamping protection circuit is connected to Hcur6, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Hpot6 and Hcur6 signals to Hch6, and their shielding nets are connected to capacitor meter 2 Guard#2.

[0062] Switching circuit mode two switching unit LCH6: one end of SW101 is connected to Lpot6, and the other end is connected to capacitor meter 2 Guard#2; one end of SW102 is connected to Lpot6, and the other end is connected to capacitor meter 2 Lpot#2; one end of the clamping TVS diode D43 in the clamping protection circuit is connected to Lpot6, and the other end is connected to capacitor meter 2 Guard#2; one end of SW103 is connected to Lcur6, and the other end is connected to capacitor meter 2 Lcur#2; one end of SW104 is connected to Lcur6, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D44 in the clamping protection circuit is connected to Lcur6, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Lpot6 and Lcur6 signals to Lch6 respectively, and their shielding nets are connected to capacitor meter 2 Guard#1.

[0063] One end of the MLCC capacitor C14 under test in CH6 is connected to Hch6, and the other end is connected to Lch6.

[0064] Switching circuit mode two switching unit HCH7: one end of SW89 is connected to Hpot7, and the other end is connected to capacitor meter 2 Guard#2; one end of SW90 is connected to Hpot7, and the other end is connected to capacitor meter 2 Hpot#2; one end of the clamping TVS diode D37 in the clamping protection circuit is connected to Hpot7, and the other end is connected to capacitor meter 2 Guard#2; one end of SW91 is connected to Hcur7, and the other end is connected to capacitor meter 2 Hcur#2; one end of SW92 is connected to Hcur7, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D38 in the clamping protection circuit is connected to Hcur7, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded wires are used between Hpot7 and Hcur7 signals to Hch7, and their shielding nets are connected to capacitor meter 2 Guard#2.

[0065] Switching circuit mode two switching unit LCH7: one end of SW105 is connected to Lpot7, and the other end is connected to capacitor meter 2 Guard#2; one end of SW106 is connected to Lpot7, and the other end is connected to capacitor meter 2 Lpot#2; one end of the clamping TVS diode D45 in the clamping protection circuit is connected to Lpot7, and the other end is connected to capacitor meter 2 Guard#2; one end of SW107 is connected to Lcur7, and the other end is connected to capacitor meter 2 Lcur#2; one end of SW108 is connected to Lcur7, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D46 in the clamping protection circuit is connected to Lcur7, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Lpot7 and Lcur7 signals to Lch7, and their shielding nets are connected to capacitor meter 2 Guard#1.

[0066] One end of the MLCC capacitor C15 under test in CH7 is connected to Hch7, and the other end is connected to Lch7.

[0067] Switching circuit mode two switching unit HCH8: one end of SW93 is connected to Hpot8, and the other end is connected to capacitor meter 2 Guard#2; one end of SW94 is connected to Hpot8, and the other end is connected to capacitor meter 2 Hpot#2; one end of the clamping TVS diode D39 in the clamping protection circuit is connected to Hpot8, and the other end is connected to capacitor meter 2 Guard#2; one end of SW95 is connected to Hcur8, and the other end is connected to capacitor meter 2 Hcur#2; one end of SW96 is connected to Hcur8, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D40 in the clamping protection circuit is connected to Hcur8, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Hpot8 and Hcur8 signals to Hch8, and their shielding nets are connected to capacitor meter 2 Guard#2.

[0068] Switching circuit mode two switching unit LCH8: one end of SW109 is connected to Lpot8, and the other end is connected to capacitor meter 2 Guard#2; one end of SW110 is connected to Lpot8, and the other end is connected to capacitor meter 2 Lpot#2; one end of the clamping TVS diode D47 in the clamping protection circuit is connected to Lpot8, and the other end is connected to capacitor meter 2 Guard#2; one end of SW111 is connected to Lcur8, and the other end is connected to capacitor meter 2 Lcur#2; one end of SW112 is connected to Lcur8, and the other end is connected to capacitor meter 2 Guard#2; one end of the clamping TVS diode D48 in the clamping protection circuit is connected to Lcur8, and the other end is connected to capacitor meter 2 Guard#2; coaxial shielded cables are used between Lpot8 and Lcur8 signals to Lch8 respectively, and their shielding nets are connected to capacitor meter 2 Guard#1.

[0069] One end of the MLCC capacitor C16 under test in CH8 is connected to Hch8, and the other end is connected to Lch8.

[0070] In switching circuit mode 2, a coaxial shielded cable is used between the Hcur#2 and Hpot#2 signals of capacitor meter 2 and the H-end CH5 to CH8 switching module, and its shielding net is connected to Guard#2 of capacitor meter 2; in switching circuit mode 2, a coaxial shielded cable is used between the Lcur#2 and Lpot#2 signals of capacitor meter 2 and the L-end CH5 to CH8 switching module, and its shielding net is connected to Guard#2 of capacitor meter 2.

[0071] Or use Figure 8The fourth connection method shown: In order to save the cost of the capacitance meter, the MLCC capacitor fast detection and sorting switching circuit method two CH1 to CH4 topology diagram is combined with the MLCC capacitor fast detection and sorting switching circuit method two CH5 to CH8 topology diagram, capacitance meter two is removed, and the capacitance meter two Guard#2 signal is connected to the capacitance meter one Guard#1, the capacitance meter two Hcur#2 signal is connected to the capacitance meter one Hcur#1, the capacitance meter two Hpot#2 signal is connected to the capacitance meter one Hpot#1, the capacitance meter two Lcur#2 signal is connected to the capacitance meter one Lcur#1, and the capacitance meter two Lpot#2 signal is connected to the capacitance meter one Lpot#1, thus forming the MLCC capacitor fast detection and sorting switching circuit method four CH1 to CH8 topology diagram.

[0072] Wherein, the switching module is installed between the capacitance meter and the MLCC capacitor to be tested; Switching circuit mode 1 and 3 The switch module is installed close to the MLCC capacitor under test. The closer, the better the anti-interference performance. Switching circuit mode 2 and 4 The installation position of the switching module is very flexible and is not affected by the layout of the test machine. The switching circuit module can be far away from the MLCC capacitor under test; Reference Fig. 9 Furthermore, in some embodiments of the present invention, the switching unit further includes: A first drive circuit, one end of the first drive circuit is electrically connected to the control unit, and the other end of the first drive circuit is electrically connected to the control end of the third H-end switch or the third L-end switch; the other end of the first drive circuit is also electrically connected to the control end of the second H-end switch or the second L-end switch; A first reverse circuit, one end of the first reverse circuit is electrically connected to the other end of the first drive circuit, and the other end of the first reverse circuit is electrically connected to the control end of the third H-end switching switch or the third L-end switching switch.

[0073] Specifically, in this embodiment, the MLCC capacitor fast detection and sorting switching circuit of the present invention is described in detail in the schematic diagram of the switching unit HCH1. Fig. 9 As shown, it includes a switching unit HCH1 switching switch SW1, a switching unit HCH1 switching switch SW2, a switching unit HCH1 switching switch SW3, a reverse circuit, and a driving circuit; MLCC capacitor fast detection sorting switching circuit method one switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW1, the first pin of the optocoupler phototransistor U3 is connected to VCC, the second pin of the optocoupler phototransistor U3 is connected to one end of the current limiting resistor R5, the other end of the current limiting resistor R5 is connected to SHch1n, the third pin of the optocoupler phototransistor U3 is respectively connected to the anode of the Zener diode D51, the anode of the Zener diode D54, the third pin of the N-channel MOS tube Q3 S source and the first pin of the N-channel MOS tube Q7 The source of the 3 pins S is connected in common, the 4th pin of the optocoupler phototransistor U3 is connected to one end of the resistor R3 and the resistor R10 respectively; the other end of the resistor R3 is connected to the cathode of the voltage stabilizing diode D51 and the gate of the 1st pin G of the N-channel MOS tube Q3 respectively, and the drain of the 2nd pin D of the N-channel MOS tube Q3 is connected to Guard#1; the other end of the resistor R10 is connected to the cathode of the voltage stabilizing diode D54 and the gate of the 1st pin G of the N-channel MOS tube Q7 respectively, and the drain of the 2nd pin D of the N-channel MOS tube Q7 is connected to Hch1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW2, the first pin of the optocoupler phototransistor U2 is connected to VCC, the second pin of the optocoupler phototransistor U2 is connected to one end of the current limiting resistor R7, the other end of the current limiting resistor R7 is connected to SHch1, the third pin of the optocoupler phototransistor U2 is respectively connected to the anode of the Zener diode D50, the anode of the Zener diode D53, the third pin of the N-channel MOS tube Q2 S source and the N-channel MOS tube Q6 The source of the third pin S is connected in common, the fourth pin of the optocoupler phototransistor U2 is connected to one end of the resistor R2 and the resistor R9 respectively; the other end of the resistor R2 is connected to the cathode of the voltage stabilizing diode D50 and the gate of the first pin G of the N-channel MOS tube Q2 respectively, and the drain of the second pin D of the N-channel MOS tube Q2 is connected to Hpot#1; the other end of the resistor R9 is connected to the cathode of the voltage stabilizing diode D53 and the gate of the first pin G of the N-channel MOS tube Q6 respectively, and the drain of the second pin D of the N-channel MOS tube Q6 is connected to Hch1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW3, the first pin of the optocoupler phototransistor U1 is connected to VCC, the second pin of the optocoupler phototransistor U1 is connected to one end of the current limiting resistor R6, the other end of the current limiting resistor R6 is connected to SHch1, the third pin of the optocoupler phototransistor U1 is respectively connected to the anode of the Zener diode D49, the anode of the Zener diode D52, the third pin of the N-channel MOS tube Q1 S source and the N-channel MOS tube Q5 The source of the third pin S is connected in common, and the fourth pin of the optocoupler phototransistor U1 is connected to one end of the resistor R1 and the resistor R8 respectively; the other end of the resistor R1 is connected to the cathode of the voltage zener diode D49 and the gate of the first pin G of the N-channel MOS tube Q1 respectively, and the drain of the second pin D of the N-channel MOS tube Q1 is connected to Hcur#1; the other end of the resistor R8 is connected to the cathode of the voltage zener diode D52 and the gate of the first pin G of the N-channel MOS tube Q5 respectively, and the drain of the second pin D of the N-channel MOS tube Q5 is connected to Hch1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram The reverse circuit of implementation 1 includes a resistor R4, an N-channel MOS tube Q4 and a filter capacitor to form a signal inverter; one end of the resistor R4 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C17 is connected to GND, and the other end is connected to SHch1; the gate of the first pin G of the N-channel MOS tube Q4 is connected to SHch1, the drain of the second pin D is connected to SHch1n, and the source of the third pin S is connected to GND; MLCC capacitor fast detection sorting switching circuit mode 1 switching unit HCH1 detailed schematic diagram The driving circuit of implementation 1 includes a resistor R11, a resistor R12 and an N-channel MOS tube Q8; one end of the resistor R11 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of the N-channel MOS tube Q8; one end of the resistor R12 is connected to GND, and the other end is the first pin G gate of the N-channel MOS tube Q8; the second pin D drain of the N-channel MOS tube Q8 is connected to SHch1; the third pin S source of the N-channel MOS tube Q8 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram Implementation 1 of the clamping protection circuit of the TVS diode D55 is connected to Hch1 at one end, and connected to the capacitance meter 2 Guard#1 at the other end; The invention discloses a MLCC capacitor rapid detection and sorting switching circuit mode, a switching unit HCH1, a detailed schematic diagram, and an implementation 2. Fig.10 As shown, it includes a switching unit HCH1 switching switch SW1, a switching unit HCH1 switching switch SW2, a switching unit HCH1 switching switch SW3, a reverse circuit, and a driving circuit; MLCC capacitor fast detection and sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW1, the first pin of the optocoupler solid-state relay_MOS output U6 is connected to VCC, the second pin of the optocoupler solid-state relay_MOS output U6 is connected to one end of the current limiting resistor R14, the other end of the current limiting resistor R14 is connected to SHch1n, the third pin of the optocoupler solid-state relay_MOS output U6 is connected to Hch1, and the fourth pin of the optocoupler solid-state relay_MOS output U6 is connected to Guard#1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW2, The first pin of the optocoupler solid-state relay_MOS output U5 is connected to VCC, the second pin of the optocoupler solid-state relay_MOS output U5 is connected to one end of the current limiting resistor R16, the other end of the current limiting resistor R16 is connected to SHch1, the third pin of the optocoupler solid-state relay_MOS output U5 is connected to Hch1, and the fourth pin of the optocoupler solid-state relay_MOS output U5 is connected to Hpot#1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW3, The first pin of the optocoupler solid-state relay_MOS output U4 is connected to VCC, the second pin of the optocoupler solid-state relay_MOS output U4 is connected to one end of the current limiting resistor R15, the other end of the current limiting resistor R15 is connected to SHch1, the third pin of the optocoupler solid-state relay_MOS output U4 is connected to Hch1, and the fourth pin of the optocoupler solid-state relay_MOS output U4 is connected to Hcur#1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 2 of the reverse circuit includes a resistor R13, an N-channel MOS tube Q9 and a filter capacitor to form a signal inverter; one end of the resistor R13 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C18 is connected to GND, and the other end is connected to SHch1; the first pin G gate of the N-channel MOS tube Q13 is connected to SHch1, the second pin D drain is connected to SHch1n, and the third pin S source is connected to GND; MLCC capacitor fast detection sorting switching circuit mode 1 switching unit HCH1 detailed schematic diagram implementation 2 driving circuit includes resistor R17, resistor R18 and N-channel MOS tube Q10; one end of resistor R17 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of N-channel MOS tube Q10; one end of resistor R18 is connected to GND, and the other end is the first pin G gate of N-channel MOS tube Q10; the second pin D drain of N-channel MOS tube Q10 is connected to SHch1; the third pin S source of N-channel MOS tube Q10 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram Implementation 2 of the clamping protection circuit of the clamping TVS diode D56 is connected to Hch1 at one end, and connected to the capacitance meter 2 Guard#1 at the other end; The invention discloses a MLCC capacitor rapid detection and sorting switching circuit mode - a switching unit HCH1 detailed schematic diagram implementation 3 description as follows Fig.11 As shown, it includes a switching unit HCH1 switching switch SW1, a switching unit HCH1 switching switch SW2, a switching unit HCH1 switching switch SW3, a reverse circuit, and a driving circuit; MLCC capacitor fast detection and sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW1, the normally open contact pin 1 of relay RLY3 is connected to Guard#1, the normally open contact pin 4 of relay RLY3 is connected to Hch1, the coil pin 2 of relay RLY3 is connected to VCC, the coil pin 3 of relay RLY3 is respectively connected to the anode of freewheeling diode D59 and one end of current limiting resistor R20, the cathode of freewheeling diode D59 is connected to VCC, and the other end of current limiting resistor R20 is connected to SHch1n; MLCC capacitor fast detection and sorting switching circuit method one switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW2, the normally open contact pin 1 of relay RLY2 is connected to Hpot#1, the normally open contact pin 4 of relay RLY2 is connected to Hch1, the coil pin 2 of relay RLY2 is connected to VCC, the coil pin 3 of relay RLY2 is respectively connected to the anode of freewheeling diode D58 and one end of current limiting resistor R22, the cathode of freewheeling diode D58 is connected to VCC, and the other end of current limiting resistor R22 is connected to SHch1; MLCC capacitor fast detection and sorting switching circuit method one switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW3, the normally open contact pin 1 of relay RLY1 is connected to Hcur#1, the normally open contact pin 4 of relay RLY1 is connected to Hch1, the coil pin 2 of relay RLY1 is connected to VCC, the coil pin 3 of relay RLY1 is respectively connected to the anode of freewheeling diode D57 and one end of current limiting resistor R21, the cathode of freewheeling diode D57 is connected to VCC, and the other end of current limiting resistor R21 is connected to SHch1; MLCC capacitor fast detection sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram Implementation 3 of the reverse circuit includes a resistor R19, an N-channel MOS tube Q11 and a filter capacitor to form a signal inverter; one end of the resistor R19 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C19 is connected to GND, and the other end is connected to SHch1; the first pin G of the N-channel MOS tube Q11 is connected to the gate of SHch1, the second pin D is connected to the drain of SHch1n, and the third pin S is connected to the source of GND; MLCC capacitor fast detection sorting switching circuit mode 1 switching unit HCH1 detailed schematic diagram implementation 3 of the driving circuit includes a resistor R23, a resistor R24 ​​and an N-channel MOS tube Q12; one end of the resistor R23 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of the N-channel MOS tube Q12; one end of the resistor R24 ​​is connected to GND, and the other end is the first pin G gate of the N-channel MOS tube Q12; the second pin D drain of the N-channel MOS tube Q12 is connected to SHch1; the third pin S source of the N-channel MOS tube Q12 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 1 switching unit HCH1 detailed schematic diagram Implementation 3 of the clamping protection circuit of the clamping TVS diode D60 is connected to Hch1 at one end, and connected to the capacitance meter 2 Guard#1 at the other end; The detailed schematic diagrams of the switching units HCH1, HCH2, HCH3, HCH4, HCH5, HCH6, HCH7, HCH8, LCH1, LCH2, LCH3, LCH4, LCH5, LCH6, LCH7, and LCH8 in the topological structure diagram of the MLCC capacitor fast detection and sorting switching circuit method 1 and the MLCC capacitor fast detection and sorting switching circuit method 3 are the same as those in implementation 1, implementation 2, and implementation 3 respectively; the control unit MCU corresponds to The control signals are Sig_Hch1, Sig_Hch2, Sig_Hch3, Sig_Hch4, Sig_Hch5, Sig_Hch6, Sig_Hch7, Sig_Hch8, Sig_Lch1, Sig_Lch2, Sig_Lch3, Sig_Lch4, Sig_Lch5, Sig_Lch6, Sig_Lch7, Sig_Lch8, and the corresponding channel switching node signals are Hch1, Hch2, Hch3, Hch4, Hch5, Hch6, Hch7, Hch8, Lch1, Lch2, Lch3, Lch4, Lch5, Lch6, Lch7, Lch8; Reference Fig.10 Furthermore, in some embodiments of the present invention, the switching unit further includes: A second drive circuit, one end of the second drive circuit is electrically connected to the control unit, and the other end of the second drive circuit is electrically connected to the control end of the fifth H-end switch or the fifth L-end switch; the other end of the second drive circuit is also electrically connected to the control end of the sixth H-end switch or the sixth L-end switch; A second reverse circuit, one end of the second reverse circuit is electrically connected to the other end of the second drive circuit, and the other end of the second reverse circuit is electrically connected to the control end of the fourth H-end switching switch or the fourth L-end switching switch; the other end of the second reverse circuit is also electrically connected to the control end of the seventh H-end switching switch or the seventh L-end switching switch.

[0074] Specifically, in this embodiment, the MLCC capacitor fast detection and sorting switching circuit mode 2 of the present invention, the switching unit HCH1 detailed schematic diagram implementation 1 is as follows Fig.10 As shown, it includes a switching unit HCH1 switching switch SW49, a switching unit HCH1 switching switch SW50, a switching unit HCH1 switching switch SW51, a switching unit HCH1 switching switch SW52, a reverse circuit, and a driving circuit; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW49, the first pin of the optocoupler phototransistor U8 is connected to VCC, the second pin of the optocoupler phototransistor U8 is connected to one end of the current limiting resistor R28, the other end of the current limiting resistor R28 is connected to SHch1n, the third pin of the optocoupler phototransistor U8 is respectively connected to the anode of the Zener diode D62, the anode of the Zener diode D64, the third pin of the N-channel MOS tube Q14 S source and the third pin of the N-channel MOS tube Q17 The source of the pin S is connected in common, the 4th pin of the optocoupler phototransistor U8 is connected to one end of the resistor R26 and the resistor R31 respectively; the other end of the resistor R26 is connected to the cathode of the voltage stabilizing diode D62 and the gate of the first pin G of the N-channel MOS tube Q14 respectively, and the drain of the second pin D of the N-channel MOS tube Q14 is connected to Guard#1; the other end of the resistor R31 is connected to the cathode of the voltage stabilizing diode D64 and the gate of the first pin G of the N-channel MOS tube Q17 respectively, and the drain of the second pin D of the N-channel MOS tube Q17 is connected to Hpot1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW50, The first pin of the optocoupler phototransistor U7 is connected to VCC, the second pin of the optocoupler phototransistor U7 is connected to one end of the current limiting resistor R29, the other end of the current limiting resistor R29 is connected to SHch1, the third pin of the optocoupler phototransistor U7 is respectively connected to the anode of the voltage zener diode D61, the anode of the voltage zener diode D63, the third pin S source of the N-channel MOS tube Q13 and the third pin S source of the N-channel MOS tube Q16, the fourth pin of the optocoupler phototransistor U7 is respectively connected to one end of the resistor R25 and the resistor R30; the other end of the resistor R25 is respectively connected to the cathode of the voltage zener diode D61 and the gate of the first pin G of the N-channel MOS tube Q13, the drain of the second pin D of the N-channel MOS tube Q13 is connected to Hpot#1; the other end of the resistor R30 is respectively connected to the cathode of the voltage zener diode D63 and the gate of the first pin G of the N-channel MOS tube Q16, the drain of the second pin D of the N-channel MOS tube Q16 is connected to Hpot1; MLCC capacitor fast detection sorting switching circuit method two switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW51, the first pin of the optocoupler phototransistor U9 is connected to VCC, the second pin of the optocoupler phototransistor U9 is connected to one end of the current limiting resistor R37, the other end of the current limiting resistor R37 is connected to SHch1, the third pin of the optocoupler phototransistor U9 is respectively connected to the anode of the Zener diode D66, the anode of the Zener diode D68, the third pin of the N-channel MOS tube Q18 S source and the third pin of the N-channel MOS tube Q21 The source of the pin S is connected in common, the 4th pin of the optocoupler phototransistor U7 is connected to one end of the resistor R32 and the resistor R38 respectively; the other end of the resistor R32 is connected to the cathode of the voltage zener diode D66 and the gate of the first pin G of the N-channel MOS tube Q18 respectively, and the drain of the second pin D of the N-channel MOS tube Q18 is connected to Hcur#1; the other end of the resistor R38 is connected to the cathode of the voltage zener diode D68 and the gate of the first pin G of the N-channel MOS tube Q21 respectively, and the drain of the second pin D of the N-channel MOS tube Q21 is connected to Hcur1; MLCC capacitor fast detection sorting switching circuit method two switching unit HCH1 detailed schematic diagram implementation 1 switching switch SW52, the first pin of the optocoupler phototransistor U10 is connected to VCC, the second pin of the optocoupler phototransistor U10 is connected to one end of the current limiting resistor R34, the other end of the current limiting resistor R34 is connected to SHch1n, the third pin of the optocoupler phototransistor U10 is respectively connected to the anode of the Zener diode D67, the anode of the Zener diode D69, the third pin of the N-channel MOS tube Q19 S source and the first pin of the N-channel MOS tube Q22 The source of the 3 pins S is connected in common, the 4th pin of the optocoupler phototransistor U10 is connected to the resistor R33 and one end of the resistor R39 respectively; the other end of the resistor R33 is connected to the cathode of the voltage zener diode D67 and the gate of the 1st pin G of the N-channel MOS tube Q19 respectively, and the drain of the 2nd pin D of the N-channel MOS tube Q19 is connected to Guard#1; the other end of the resistor R39 is connected to the cathode of the voltage zener diode D69 and the gate of the 1st pin G of the N-channel MOS tube Q22 respectively, and the drain of the 2nd pin D of the N-channel MOS tube Q22 is connected to Hcur1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 1 of the reverse circuit includes a resistor R27, an N-channel MOS tube Q15 and a filter capacitor to form a signal inverter; one end of the resistor R27 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C20 is connected to GND, and the other end is connected to SHch1; the first pin G gate of the N-channel MOS tube Q15 is connected to SHch1, the second pin D drain is connected to SHch1n, and the third pin S source is connected to GND; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 1 of the driving circuit includes a resistor R35, a resistor R36 and an N-channel MOS tube Q20; one end of the resistor R35 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of the N-channel MOS tube Q20; one end of the resistor R36 is connected to GND, and the other end is the first pin G gate of the N-channel MOS tube Q20; the second pin D drain of the N-channel MOS tube Q20 is connected to SHch1; the third pin S source of the N-channel MOS tube Q20 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 1 clamping protection circuit includes clamping TVS diodes D65 and D70, one end of the clamping TVS diode D65 is connected to Hpot1, and the other end is connected to the capacitance meter Guard#1; one end of the clamping TVS diode D70 is connected to Hcur1, and the other end is connected to the capacitance meter Guard#1; The invention discloses a MLCC capacitor rapid detection and sorting switching circuit mode 2 switching unit HCH1 detailed schematic diagram implementation 2 description as follows Fig.11 As shown, it includes a switching unit HCH1 switching switch SW49, a switching unit HCH1 switching switch SW50, a switching unit HCH1 switching switch SW51, a switching unit HCH1 switching switch SW52, a reverse circuit, and a driving circuit; MLCC capacitor fast detection and sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW49, the first pin of the optocoupler solid-state relay (MOS output) U12 is connected to VCC, the second pin of the optocoupler solid-state relay (MOS output) U12 is connected to one end of the current limiting resistor R41, and the other end of the current limiting resistor R41 is connected to SHch1n, the third pin of the optocoupler solid-state relay (MOS output) U12 is connected to Hpot1, and the fourth pin of the optocoupler solid-state relay (MOS output) U12 is connected to Guard#1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW50, The first pin of the optocoupler solid-state relay (MOS output) U11 is connected to VCC, the second pin of the optocoupler solid-state relay (MOS output) U11 is connected to one end of the current limiting resistor R42, the other end of the current limiting resistor R42 is connected to SHch1, the third pin of the optocoupler solid-state relay (MOS output) U11 is connected to Hpot1, and the fourth pin of the optocoupler solid-state relay (MOS output) U11 is connected to Hpot#1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 2 switching switch SW51, The first pin of the optocoupler solid-state relay (MOS output) U13 is connected to VCC, the second pin of the optocoupler solid-state relay (MOS output) U13 is connected to one end of the current limiting resistor R46, the other end of the current limiting resistor R46 is connected to SHch1, the third pin of the optocoupler solid-state relay (MOS output) U13 is connected to Hcur1, and the fourth pin of the optocoupler solid-state relay (MOS output) U13 is connected to Hcur#1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic implementation 2 switching switch SW52, The first pin of the optocoupler solid-state relay (MOS output) U14 is connected to VCC, the second pin of the optocoupler solid-state relay (MOS output) U14 is connected to one end of the current limiting resistor R43, the other end of the current limiting resistor R43 is connected to SHch1n, the third pin of the optocoupler solid-state relay (MOS output) U14 is connected to Hcur1, and the fourth pin of the optocoupler solid-state relay (MOS output) U14 is connected to Guard#1; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 2 The reverse circuit includes a resistor R40, an N-channel MOS tube Q23 and a filter capacitor to form a signal inverter; one end of the resistor R40 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C21 is connected to GND, and the other end is connected to SHch1; the first pin G of the N-channel MOS tube Q23 is connected to the gate of SHch1, the second pin D is connected to the drain of SHch1n, and the third pin S is connected to the source of GND; MLCC capacitor fast detection sorting switching circuit mode 1 switching unit HCH1 detailed schematic diagram implementation 2 driving circuit includes resistor R44, resistor R45 and N-channel MOS tube Q24; one end of resistor R44 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of N-channel MOS tube Q23; one end of resistor R45 is connected to GND, and the other end is the first pin G gate of N-channel MOS tube Q24; the second pin D drain of N-channel MOS tube Q24 is connected to SHch1; the third pin S source of N-channel MOS tube Q24 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 2 clamping protection circuit includes clamping TVS diodes D71 and D72, one end of the clamping TVS diode D71 is connected to Hpot1, and the other end is connected to the capacitance meter Guard#1; one end of the clamping TVS diode D72 is connected to Hcur1, and the other end is connected to the capacitance meter Guard#1; The invention discloses a MLCC capacitor rapid detection and sorting switching circuit mode 2, a switching unit HCH1, a detailed schematic diagram, and an implementation 3. Fig.12As shown, it includes a switching unit HCH1 switching switch SW49, a switching unit HCH1 switching switch SW50, a switching unit HCH1 switching switch SW51, a switching unit HCH1 switching switch SW52, a reverse circuit, and a driving circuit; MLCC capacitor fast detection and sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW49, the normally open contact pin 1 of relay RLY5 is connected to Guard#1, the normally open contact pin 4 of relay RLY5 is connected to Hpot1, the coil pin 2 of relay RLY5 is connected to VCC, the coil pin 3 of relay RLY5 is respectively connected to the anode of freewheeling diode D74 and one end of current limiting resistor R48, the cathode of freewheeling diode D74 is connected to VCC, and the other end of current limiting resistor R48 is connected to SHch1n; MLCC capacitor fast detection and sorting switching circuit method two switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW50, the normally open contact pin 1 of relay RLY4 is connected to Hpot#1, the normally open contact pin 4 of relay RLY4 is connected to Hpot1, the coil pin 2 of relay RLY4 is connected to VCC, the coil pin 3 of relay RLY4 is respectively connected to the anode of freewheeling diode D73 and one end of current limiting resistor R49, the cathode of freewheeling diode D73 is connected to VCC, and the other end of current limiting resistor R49 is connected to SHch1; MLCC capacitor fast detection and sorting switching circuit method two switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW51, the normally open contact pin 1 of relay RLY6 is connected to Hcur#1, the normally open contact pin 4 of relay RLY6 is connected to Hcur1, the coil pin 2 of relay RLY6 is connected to VCC, the coil pin 3 of relay RLY6 is respectively connected to the anode of freewheeling diode D76 and one end of current limiting resistor R52, the cathode of freewheeling diode D76 is connected to VCC, and the other end of current limiting resistor R52 is connected to SHch1; MLCC capacitor fast detection and sorting switching circuit method two switching unit HCH1 detailed schematic diagram implementation 3 switching switch SW52, the normally open contact pin 1 of relay RLY7 is connected to Guard#1, the normally open contact pin 4 of relay RLY7 is connected to Hcur1, the coil pin 2 of relay RLY7 is connected to VCC, the coil pin 3 of relay RLY7 is respectively connected to the anode of freewheeling diode D77 and one end of current limiting resistor R53, the cathode of freewheeling diode D77 is connected to VCC, and the other end of current limiting resistor R53 is connected to SHch1n; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 3 of the reverse circuit includes a resistor R47, an N-channel MOS tube Q25 and a filter capacitor to form a signal inverter; one end of the resistor R47 is connected to VCC, and the other end is connected to SHch1; one end of the filter capacitor C22 is connected to GND, and the other end is connected to SHch1; the first pin G gate of the N-channel MOS tube Q25 is connected to SHch1, the second pin D drain is connected to SHch1n, and the third pin S source is connected to GND; MLCC capacitor fast detection sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 3 of the driving circuit includes a resistor R50, a resistor R51 and an N-channel MOS tube Q26; one end of the resistor R50 is connected to the control unit Sig_Hch1, and the other end is the first pin G gate of the N-channel MOS tube Q26; one end of the resistor R51 is connected to GND, and the other end is the first pin G gate of the N-channel MOS tube Q26; the second pin D drain of the N-channel MOS tube Q26 is connected to SHch1; the third pin S source of the N-channel MOS tube Q26 is connected to GND; MLCC capacitor fast detection and sorting switching circuit method 2 switching unit HCH1 detailed schematic diagram implementation 3 clamping protection circuit includes clamping TVS diodes D75 and D78, one end of the clamping TVS diode D75 is connected to Hpot1, and the other end is connected to the capacitance meter 2 Guard#1; one end of the clamping TVS diode D78 is connected to Hcur1, and the other end is connected to the capacitance meter 2 Guard#1; The detailed schematic diagrams of the switching units HCH1, HCH2, HCH3, HCH4, HCH5, HCH6, HCH7, HCH8, LCH1, LCH2, LCH3, LCH4, LCH5, LCH6, LCH7, and LCH8 in the topological structure diagram of the MLCC capacitor fast detection and sorting switching circuit mode 2 and 4 CH1 to CH8 are the same as those in implementation 1, implementation 2, and implementation 3 respectively; the control unit MCU corresponds to The control signals are Sig_Hch1, Sig_Hch2, Sig_Hch3, Sig_Hch4, Sig_Hch5, Sig_Hch6, Sig_Hch7, Sig_Hch8, Sig_Lch1, Sig_Lch2, Sig_Lch3, Sig_Lch4, Sig_Lch5, Sig_Lch6, Sig_Lch7, Sig_Lch8, and the corresponding channel switching node signals are Hch1, Hch2, Hch3, Hch4, Hch5, Hch6, Hch7, Hch8, Lch1, Lch2, Lch3, Lch4, Lch5, Lch6, Lch7, Lch8; In the principle waveforms of the MLCC capacitor fast detection and sorting switching circuit methods one, two, three and four, a high level of the switching switch SW indicates conduction, and a low level indicates disconnection.

[0075] Reference Figure 1 The present invention also proposes a multi-channel testing method for MLCC capacitors, comprising the following steps: S100: When the host computer does not output a trigger signal to the control unit, the control unit outputs a first control signal to the switching module, and the switching module connects the MLCC capacitor under test to the clamping protection circuit; S200: When the host computer outputs a trigger signal to the control unit, the control unit determines that the test is allowed to start; S300: When the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal, and performs the test; S400: When the MLCC capacitors under test in all channels are tested, the control unit changes the level of the trigger signal, indicating that the test is completed.

[0076] Further, in some embodiments of the present invention, step S300: when the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal, and performs the test, including: (1) When the test starts, the control unit outputs a high-level control signal to the corresponding switching unit according to a preset timing, and the corresponding switching unit connects the corresponding MLCC capacitor under test to the capacitance meter and disconnects the corresponding clamping protection circuit, thereby performing a capacitance parameter test on the corresponding MLCC capacitor under test; (2) When the corresponding MLCC capacitor under test completes the test, the control unit outputs a low-level control signal to the corresponding switching unit, and the corresponding switching unit disconnects the corresponding MLCC capacitor under test from the capacitance meter and connects to the corresponding clamping protection circuit to form a discharge loop.

[0077] Specifically, in the above two embodiments of the multi-channel test method for MLCC capacitors, according to the multi-channel test circuit of the MLCC capacitor, there are different signal output timing waveforms, referring to Figures 15 to 18 , respectively as follows: MLCC capacitor fast detection sorting switching circuit mode 1 CH1 to CH8 working principle and logic waveform diagram as shown below Fig.15 As shown, the control logic and data of each capacitor are measured in detail as follows: From t0 to t1 and after t10: Trigger signal low level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; By default, the two ends of the capacitors C1, C2, C3, and C4 under test are connected to Guard#1, and the two ends of the capacitors C5, C6, C7, and C8 under test are connected to Guard#2. That is, the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test each form a discharge circuit for discharge to avoid residual high voltage in the capacitors under test and damage to the capacitance meter; Time periods from t1 to t2, t3 to t4, t5 to t6, t7 to t8, t9 to t10: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitors C1, C2, C3, and C4 under test are connected to Guard#1, and the two ends of the capacitors C5, C6, C7, and C8 under test are connected to Guard#2. That is, the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test form a discharge circuit to discharge respectively, so as to avoid the residual high voltage of the capacitors under test and damage the capacitance meter. At the same time, it is also ready to switch the corresponding capacitance meter measurement channel. Time period from t2 to t3: Trigger signal high level; The switching unit HCH1 controls the signal Sig_Hch1 to be high level, the switch SW1 is disconnected, and the switches SW2 and SW3 are turned on; The switching unit LCH1 control signal Sig_Lch1 is at a high level, the switch SW25 is turned off, and the switches SW26 and SW27 are turned on; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a high level, the switching switch SW3 is turned off, and the switching switches SW14 and SW15 are turned on; The control signal Sig_Lch5 of the switching unit LCH5 is at a high level, the switching switch SW37 is turned off, and the switching switches SW38 and SW39 are turned on; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitors C2, C3, and C4 under test are connected to Guard#1, and the two ends of the capacitors C6, C7, and C8 under test are connected to Guard#2, that is, the capacitors C2, C3, C4, C6, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C1 under test of CH1 are connected to the capacitance meter Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; the two ends of the capacitor C5 under test of CH5 are connected to the capacitance meter Hcur#2, Hpot#2, Lpot#2, and Lcur#2 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meters 1 and 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH1 channel C1, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH5 channel C5; Time period from T4 to t5: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a high level, the switching switch SW4 is turned off, and the switching switches SW5 and SW6 are turned on; The switching unit LCH2 control signal Sig_Lch2 is at a high level, the switching switch SW28 is turned off, and the switching switches SW29 and SW30 are turned on; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a high level, the switching switch SW16 is turned off, and the switching switches SW17 and SW18 are turned on; The control signal Sig_Lch6 of the switching unit LCH6 is at a high level, the switching switch SW40 is turned off, and the switching switches SW41 and SW42 are turned on; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitors C1, C3, and C4 under test are connected to Guard#1, and the two ends of the capacitors C5, C7, and C8 under test are connected to Guard#2, that is, the capacitors C1, C3, C4, C5, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C2 under test of CH2 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, forming a 4-wire measurement; the two ends of the capacitor C6 under test of CH6 are respectively connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of the capacitance meter 2, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meters 1 and 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH2 channel C2, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH2 channel C6; Time period from T6 to t7: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 controls the signal Sig_Hch3 to be high level, the switch SW7 is turned off, and the switches SW8 and SW9 are turned on; The control signal Sig_Lch3 of the switching unit LCH3 is high level, the switching switch SW31 is turned off, and the switching switches SW32 and SW33 are turned on; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a high level, the switching switch SW19 is turned off, and the switching switches SW20 and SW21 are turned on; The control signal Sig_Lch7 of the switching unit LCH7 is at a high level, the switching switch SW43 is turned off, and the switching switches SW44 and SW45 are turned on; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitors C1, C2, and C4 under test are connected to Guard#1, and the two ends of the capacitors C5, C6, and C8 under test are connected to Guard#2, that is, the capacitors C1, C2, C4, C5, C6, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C3 under test of CH3 are connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of capacitance meter 1, respectively, to form a 4-wire measurement; the two ends of the capacitor C7 under test of CH7 are connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of capacitance meter 2, respectively, to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meter 1 and capacitance meter 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH3 channel C3, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH7 channel C7; Time period from T8 to T9: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The switching unit LCH3 control signal Sig_Lch3 is at a low level; the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a high level, the switching switch SW10 is turned off, and the switching switches SW11 and SW12 are turned on; The control signal Sig_Lch4 of the switching unit LCH4 is at a high level, the switching switch SW34 is turned off, and the switching switches SW35 and SW36 are turned on; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a high level, the switching switch SW22 is turned off, and the switching switches SW23 and SW24 are turned on; The control signal Sig_Lch8 of the switching unit LCH8 is at a high level, the switching switch SW46 is turned off, and the switching switches SW47 and SW48 are turned on; The two ends of the capacitors C1, C2, and C3 under test are connected to Guard#1, and the two ends of the capacitors C5, C6, and C7 under test are connected to Guard#2, that is, the capacitors C1, C2, C3, C5, C6, and C7 under test each form a discharge circuit for discharge; The two ends of the capacitor C4 under test of CH4 are connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, respectively, to form a 4-wire measurement; the two ends of the capacitor C8 under test of CH8 are connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of the capacitance meter 2, respectively, to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meters 1 and 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH4 channel C4, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of CH8 channel C8; MLCC capacitor fast detection sorting switching circuit mode 2 working principle and logic waveform diagram as shown below Fig.16 As shown, the control logic and data of each capacitor are measured in detail as follows: From t0 to t1 and after t10: Trigger signal low level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; By default, the two ends of the capacitors C9, C10, C11, and C12 under test are connected to Guard#1, and the two ends of the capacitors C13, C14, C15, and C16 under test are connected to Guard#2 by default, that is, the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test each form a discharge circuit for discharge to avoid residual high voltage in the capacitors under test and damage to the capacitance meter; Time periods from t1 to t2, t3 to t4, t5 to t6, t7 to t8, t9 to t10: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; The two ends of the capacitors C9, C10, C11, and C12 under test are connected to Guard#1, and the two ends of the capacitors C13, C14, C15, and C16 under test are connected to Guard#2, that is, the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test form a discharge circuit to discharge respectively, so as to avoid the residual high voltage of the capacitors under test and damage the capacitance meter, and also to prepare for switching the corresponding capacitance meter measurement channel; Time period from t2 to t3: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a high level, the switching switches SW49 and SW52 are turned off, and the switching switches SW50 and SW51 are turned on; The control signal Sig_Lch1 of the switching unit LCH1 is at a high level, the switching switches SW81 and SW84 are turned off, and the switching switches SW82 and SW83 are turned on; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a high level, the switching switches SW65 and SW68 are turned off, and the switching switches SW66 and SW67 are turned on; The control signal Sig_Lch5 of the switching unit LCH5 is low-high level, the switching switches SW97 and SW100 are disconnected, and the switching switches SW98 and SW99 are turned on; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; The two ends of the capacitors C10, C11, and C12 under test are connected to Guard#1, and the two ends of the capacitors C14, C15, and C16 under test are connected to Guard#2, that is, the capacitors C10, C11, C12, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C9 under test of CH1 are connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of capacitance meter 1, respectively, to form a 4-wire measurement; the two ends of the capacitor C13 under test of CH5 are connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of capacitance meter 2, respectively, to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meter 1 and capacitance meter 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C9 of CH1 channel, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C13 of CH5 channel; Time period from T4 to t5: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a high level, the switching switches SW53 and SW56 are turned off, and the switching switches SW54 and SW55 are turned on; The switching unit LCH2 control signal Sig_Lch2 is at a high level, the switching switches SW85 and SW88 are turned off, and the switching switches SW86 and SW87 are turned on; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a high level, the switching switches SW69 and SW72 are turned off, and the switching switches SW70 and SW71 are turned on; The control signal Sig_Lch6 of the switching unit LCH6 is at a high level, the switching switches SW101 and SW104 are turned off, and the switching switches SW102 and SW103 are turned on; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; The two ends of the capacitors C9, C11, and C12 under test are connected to Guard#1, and the two ends of the capacitors C13, C15, and C16 under test are connected to Guard#2, that is, the capacitors C9, C11, C12, C13, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C10 under test of CH2 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, forming a 4-wire measurement; the two ends of the capacitor C14 under test of CH6 are respectively connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of the capacitance meter 2, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meters 1 and 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C10 of CH2 channel, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C14 of CH6 channel; Time period from T6 to t7: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The control signal Sig_Hch3 of the switching unit HCH3 is at a high level, the switching switches SW57 and SW60 are turned off, and the switching switches SW58 and SW59 are turned on; The switching unit LCH3 control signal Sig_Lch3 is at a high level, the switching switches SW89 and SW92 are turned off, and the switching switches SW90 and SW91 are turned on; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a high level, the switching switches SW73 and SW76 are turned off, and the switching switches SW74 and SW75 are turned on; The control signal Sig_Lch7 of the switching unit LCH7 is at a high level, the switching switches SW105 and SW108 are turned off, and the switching switches SW106 and SW107 are turned on; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; The two ends of the capacitors C9, C10, and C12 under test are connected to Guard#1, and the two ends of the capacitors C13, C14, and C16 under test are connected to Guard#2, that is, the capacitors C9, C10, C12, C13, C14, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C11 under test of CH3 are connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of capacitance meter 1, respectively, to form a 4-wire measurement; the two ends of the capacitor C15 under test of CH7 are connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of capacitance meter 2, respectively, to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meter 1 and capacitance meter 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C11 of CH3 channel, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C15 of CH7 channel; Time period from T8 to T9: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a high level, the switching switches SW61 and SW64 are turned off, and the switching switches SW62 and SW63 are turned on; The control signal Sig_Lch4 of the switching unit LCH4 is at a high level, the switching switches SW93 and SW96 are turned off, and the switching switches SW94 and SW95 are turned on; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a high level, the switching switches SW77 and SW80 are turned off, and the switching switches SW78 and SW79 are turned on; The control signal Sig_Lch8 of the switching unit LCH8 is at a high level, the switching switches SW109 and SW112 are turned off, and the switching switches SW110 and SW111 are turned on; The two ends of the capacitors C9, C10, and C11 under test are connected to Guard#1, and the two ends of the capacitors C13, C14, and C15 under test are connected to Guard#2, that is, the capacitors C9, C10, C11, C13, C14, and C15 under test each form a discharge circuit for discharge; The two ends of the capacitor C12 under test of CH4 are connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of capacitance meter 1, respectively, to form a 4-wire measurement; the two ends of the capacitor C16 under test of CH8 are connected to Hcur#2, Hpot#2, Lpot#2, and Lcur#2 of capacitance meter 2, respectively, to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meter 1 and capacitance meter 2, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C12 of CH4 channel, and capacitance meter 2 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C16 of CH8 channel; MLCC capacitor fast detection sorting switching circuit mode three working principle and logic waveform diagram as shown below Fig.17 As shown, the control logic and data of each capacitor are measured in detail as follows: From t0 to t1 and after t10: Trigger signal low level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; By default, both ends of the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test are connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test each form a discharge circuit for discharge to avoid residual high voltage in the capacitors under test and damage to the capacitance meter; Time periods t1 to t2, t3 to t4, t5 to t6, t7 to t8, t9 to t10, t11 to t12, t13 to t14, t15 to t16, t17 to t18: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test are connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C5, C6, C7, and C8 under test form a discharge circuit for discharge respectively, to avoid residual high voltage in the capacitors under test and damage to the capacitance meter, and also to prepare for switching the corresponding capacitance meter measurement channel; Time period from t2 to t3: Trigger signal high level; The switching unit HCH1 controls the signal Sig_Hch1 to be high level, the switch SW1 is disconnected, and the switches SW2 and SW3 are turned on; The switching unit LCH1 control signal Sig_Lch1 is at a high level, the switch SW25 is turned off, and the switches SW26 and SW27 are turned on; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C2, C3, C4, C5, C6, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C2, C3, C4, C5, C6, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C1 under test in CH1 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH1 channel C1; Time period from T4 to t5: Trigger signal high level; Both ends of the capacitors C1, C3, C4, C5, C6, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C3, C4, C5, C6, C7, and C8 under test each form a discharge circuit for discharge; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a high level, the switching switch SW4 is turned off, and the switching switches SW5 and SW6 are turned on; The switching unit LCH2 control signal Sig_Lch2 is at a high level, the switching switch SW28 is turned off, and the switching switches SW29 and SW30 are turned on; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitor C2 under test in CH2 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH2 channel C2; Time period from T6 to t7: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 controls the signal Sig_Hch3 to be high level, the switch SW7 is turned off, and the switches SW8 and SW9 are turned on; The control signal Sig_Lch3 of the switching unit LCH3 is high level, the switching switch SW31 is turned off, and the switching switches SW32 and SW33 are turned on; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C1, C2, C4, C5, C6, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C2, C4, C5, C6, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C3 under test in CH3 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH3 channel C3; Time period from T8 to T9: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a high level, the switching switch SW10 is turned off, and the switching switches SW11 and SW12 are turned on; The control signal Sig_Lch4 of the switching unit LCH4 is at a high level, the switching switch SW34 is turned off, and the switching switches SW35 and SW36 are turned on; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C1, C2, C3, C5, C6, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C2, C3, C5, C6, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C4 under test in CH4 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH4 channel C4; Time period from T10 to t11: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a high level, the switching switch SW3 is turned off, and the switching switches SW14 and SW15 are turned on; The control signal Sig_Lch5 of the switching unit LCH5 is at a high level, the switching switch SW37 is turned off, and the switching switches SW38 and SW39 are turned on; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C1, C2, C3, C4, C6, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C6, C7, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C5 under test in CH5 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH5 channel C5; Time period from T12 to t13: Trigger signal high level; Both ends of the capacitors C1, C2, C3, C4, C5, C7, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C5, C7, and C8 under test each form a discharge circuit for discharge; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a high level, the switching switch SW16 is turned off, and the switching switches SW17 and SW18 are turned on; The control signal Sig_Lch6 of the switching unit LCH6 is at a high level, the switching switch SW40 is turned off, and the switching switches SW41 and SW42 are turned on; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; The two ends of the capacitor C6 under test in CH6 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH6 channel C6; Time period from T14 to t15: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a high level, the switching switch SW19 is turned off, and the switching switches SW20 and SW21 are turned on; The control signal Sig_Lch7 of the switching unit LCH7 is at a high level, the switching switch SW43 is turned off, and the switching switches SW44 and SW45 are turned on; The switching unit HCH8 controls the signal Sig_Hch8 to be low level, the switching switch SW22 is turned on, and the switching switches SW23 and SW24 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switch SW46 is turned on, and the switching switches SW47 and SW48 are turned off; Both ends of the capacitors C1, C2, C3, C4, C5, C6, and C8 under test remain connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C5, C6, and C8 under test each form a discharge circuit for discharge; The two ends of the capacitor C7 under test of CH7 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH7 channel C7; Time period from T16 to t7: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a low level, the switching switch SW1 is turned on, and the switching switches SW2 and SW3 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switch SW25 is turned on, and the switching switches SW26 and SW27 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switch SW4 is turned on, and the switching switches SW5 and SW6 are turned off; The control signal Sig_Lch2 of the switching unit LCH2 is at a low level, the switching switch SW28 is turned on, and the switching switches SW29 and SW30 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switch SW7 is turned on, and the switching switches SW8 and SW9 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switch SW31 is turned on, and the switching switches SW32 and SW33 are turned off; The switching unit HCH4 control signal Sig_Hch4 is at a low level, the switching switch SW10 is turned on, and the switching switches SW11 and SW12 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switch SW34 is turned on, and the switching switches SW35 and SW36 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switch SW3 is turned on, and the switching switches SW14 and SW15 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switch SW37 is turned on, and the switching switches SW38 and SW39 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switch SW16 is turned on, and the switching switches SW17 and SW18 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switch SW40 is turned on, and the switching switches SW41 and SW42 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switch SW19 is turned on, and the switching switches SW20 and SW21 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switch SW43 is turned on, and the switching switches SW44 and SW45 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a high level, the switching switch SW22 is turned off, and the switching switches SW23 and SW24 are turned on; The control signal Sig_Lch8 of the switching unit LCH8 is at a high level, the switching switch SW46 is turned off, and the switching switches SW47 and SW48 are turned on; Both ends of the capacitors C1, C2, C3, C4, C5, C6, and C7 under test remain connected to Guard#1, that is, the capacitors C1, C2, C3, C4, C5, C6, and C7 under test each form a discharge circuit for discharge; The two ends of the capacitor C8 under test in CH8 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH8 channel C8; MLCC capacitor fast detection sorting switching circuit mode 4 working principle and logic waveform diagram as shown below Fig.18 As shown, the control logic and data for measuring each capacitor in detail are as follows: From t0 to t1 and after t10: Trigger signal low level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; By default, both ends of the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test are connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test each form a discharge circuit for discharge to avoid residual high voltage in the capacitors under test and damage to the capacitance meter; Time periods t1 to t2, t3 to t4, t5 to t6, t7 to t8, t9 to t10, t11 to t12, t13 to t14, t15 to t16, t17 to t18: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test are connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C13, C14, C15, and C16 under test form a discharge circuit for discharge respectively, to avoid residual high voltage in the capacitors under test and damage to the capacitance meter, and also to prepare for switching the corresponding capacitance meter measurement channel; Time period from t2 to t3: Trigger signal high level; The control signal Sig_Hch1 of the switching unit HCH1 is at a high level, the switching switches SW49 and SW52 are turned off, and the switching switches SW50 and SW51 are turned on; The control signal Sig_Lch1 of the switching unit LCH1 is at a high level, the switching switches SW81 and SW84 are turned off, and the switching switches SW82 and SW83 are turned on; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C10, C11, C12, C13, C14, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C10, C11, C12, C13, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C9 under test in CH1 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C9 in the CH1 channel; Time period from T4 to t5: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a high level, the switching switches SW53 and SW56 are turned off, and the switching switches SW54 and SW55 are turned on; The switching unit LCH2 control signal Sig_Lch2 is at a high level, the switching switches SW85 and SW88 are turned off, and the switching switches SW86 and SW87 are turned on; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C11, C12, C13, C14, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C11, C12, C13, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C10 under test in CH2 are respectively connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH2 channel C10; Time period from T6 to t7: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The control signal Sig_Hch3 of the switching unit HCH3 is at a high level, the switching switches SW57 and SW60 are turned off, and the switching switches SW58 and SW59 are turned on; The switching unit LCH3 control signal Sig_Lch3 is at a high level, the switching switches SW89 and SW92 are turned off, and the switching switches SW90 and SW91 are turned on; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C12, C13, C14, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C10, C12, C13, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C11 under test in CH3 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH3 channel C11; Time period from T8 to T9: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a high level, the switching switches SW61 and SW64 are disconnected, and the switching switches SW62 and SW63 are turned on; The control signal Sig_Lch4 of the switching unit LCH4 is at a high level, the switching switches SW93 and SW96 are turned off, and the switching switches SW94 and SW95 are turned on; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C11, C13, C14, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C10, C11, C13, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C12 under test in CH4 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH4 channel C12; Time period from T10 to t11: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a high level, the switching switches SW65 and SW68 are turned off, and the switching switches SW66 and SW67 are turned on; The control signal Sig_Lch5 of the switching unit LCH5 is at a high level, the switching switches SW97 and SW100 are turned off, and the switching switches SW98 and SW99 are turned on; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C11, C12, C14, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C14, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C13 under test in CH5 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, and Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH5 channel C13; Time period from T12 to t13: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a high level, the switching switches SW69 and SW72 are turned off, and the switching switches SW70 and SW71 are turned on; The control signal Sig_Lch6 of the switching unit LCH6 is at a high level, the switching switches SW101 and SW104 are turned off, and the switching switches SW102 and SW103 are turned on; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C11, C12, C13, C15, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C13, C15, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C14 under test of CH6 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of the capacitance meter 1, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C6 of the CH14 channel; Time period from T14 to t15: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a high level, the switching switches SW73 and SW76 are turned off, and the switching switches SW74 and SW75 are turned on; The control signal Sig_Lch7 of the switching unit LCH7 is at a high level, the switching switches SW105 and SW108 are turned off, and the switching switches SW106 and SW107 are turned on; The control signal Sig_Hch8 of the switching unit HCH8 is at a low level, the switching switches SW77 and SW80 are turned on, and the switching switches SW78 and SW79 are turned off; The control signal Sig_Lch8 of the switching unit LCH8 is at a low level, the switching switches SW109 and SW112 are turned on, and the switching switches SW110 and SW111 are turned off; Both ends of the capacitors C9, C10, C11, C12, C13, C14, and C16 under test remain connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C13, C14, and C16 under test each form a discharge circuit for discharge; The two ends of the capacitor C15 under test of CH7 are connected to the capacitance meter 1 Hcur#1, Hpot#1, Lpot#1, Lcur#1 respectively, forming a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​the capacitance meter 1, in the high level time area, the capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of the CH7 channel C15; Time period from T16 to t7: Trigger signal high level; The switching unit HCH1 control signal Sig_Hch1 is at a low level, the switching switches SW49 and SW52 are turned on, and the switching switches SW50 and SW51 are turned off; The control signal Sig_Lch1 of the switching unit LCH1 is at a low level, the switching switches SW81 and SW84 are turned on, and the switching switches SW82 and SW83 are turned off; The switching unit HCH2 control signal Sig_Hch2 is at a low level, the switching switches SW53 and SW56 are turned on, and the switching switches SW54 and SW55 are turned off; The switching unit LCH2 control signal Sig_Lch2 is at a low level, the switching switches SW85 and SW88 are turned on, and the switching switches SW86 and SW87 are turned off; The switching unit HCH3 control signal Sig_Hch3 is at a low level, the switching switches SW57 and SW60 are turned on, and the switching switches SW58 and SW59 are turned off; The control signal Sig_Lch3 of the switching unit LCH3 is at a low level, the switching switches SW89 and SW92 are turned on, and the switching switches SW90 and SW91 are turned off; The control signal Sig_Hch4 of the switching unit HCH4 is at a low level, the switching switches SW61 and SW64 are turned on, and the switching switches SW62 and SW63 are turned off; The control signal Sig_Lch4 of the switching unit LCH4 is at a low level, the switching switches SW93 and SW96 are turned on, and the switching switches SW94 and SW95 are turned off; The control signal Sig_Hch5 of the switching unit HCH5 is at a low level, the switching switches SW65 and SW68 are turned on, and the switching switches SW66 and SW67 are turned off; The control signal Sig_Lch5 of the switching unit LCH5 is at a low level, the switching switches SW97 and SW100 are turned on, and the switching switches SW98 and SW99 are turned off; The control signal Sig_Hch6 of the switching unit HCH6 is at a low level, the switching switches SW69 and SW72 are turned on, and the switching switches SW70 and SW71 are turned off; The control signal Sig_Lch6 of the switching unit LCH6 is at a low level, the switching switches SW101 and SW104 are turned on, and the switching switches SW102 and SW103 are turned off; The control signal Sig_Hch7 of the switching unit HCH7 is at a low level, the switching switches SW73 and SW76 are turned on, and the switching switches SW74 and SW75 are turned off; The control signal Sig_Lch7 of the switching unit LCH7 is at a low level, the switching switches SW105 and SW108 are turned on, and the switching switches SW106 and SW107 are turned off; The control signal Sig_Hch8 of the switching unit HCH8 is at a high level, the switching switches SW77 and SW80 are turned off, and the switching switches SW78 and SW79 are turned on; The control signal Sig_Lch8 of the switching unit LCH8 is at a high level, the switching switches SW109 and SW112 are turned off, and the switching switches SW110 and SW111 are turned on; Both ends of the capacitors C9, C10, C11, C12, C13, C14, and C15 under test remain connected to Guard#1, that is, the capacitors C9, C10, C11, C12, C13, C14, and C15 under test each form a discharge circuit for discharge; The two ends of the capacitor C16 under test of CH8 are respectively connected to Hcur#1, Hpot#1, Lpot#1, and Lcur#1 of capacitance meter 1 to form a 4-wire measurement; in the waveform diagram of the data acquisition area of ​​capacitance meter 1, in the high level time area, capacitance meter 1 measures the capacitance value and dielectric loss factor (DF, Dissipation Factor) of C16 of CH8 channel.

[0078] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A multi-channel test circuit for MLCC capacitors, characterized in that: include: Several MLCC capacitors under test; A switching module, wherein an input end of the switching module is electrically connected to the MLCC capacitor under test; A control unit, the control unit is electrically connected to the control end of the switching module, and the control unit is also used to be electrically connected to a host computer; A plurality of capacitance meters, wherein the capacitance meters are electrically connected to the control unit and are also electrically connected to the output end of the switching module; A plurality of clamping protection circuits, one end of each clamping protection circuit is electrically connected to the input end of the switching module, and the other end of each clamping protection circuit is electrically connected to the capacitance meter.

2. The multi-channel test circuit for MLCC capacitors according to claim 1, characterized in that: The switching module includes a plurality of switching units, and the switching units are divided into an H-end switching unit and an L-end switching unit, and the H-end switching unit corresponds to the L-end switching unit one by one; The H-end switching units correspond to the MLCC capacitors under test one by one, the input ends of the H-end switching units are electrically connected to the high level ends of the corresponding MLCC capacitors under test, and the output ends of the H-end switching units are electrically connected to the capacitance meter; The L-end switching unit corresponds one-to-one to the MLCC capacitor under test, the input end of the L-end switching unit is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and the output end of the L-end switching unit is electrically connected to the capacitance meter.

3. The multi-channel test circuit of the MLCC capacitor according to claim 2, characterized in that: The clamping protection circuit includes: a clamping protection TVS diode, the clamping protection TVS diode corresponds to the switching unit one by one, one end of the clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the clamping protection TVS diode is electrically connected to the protection terminal of the capacitance meter; The H-end switching unit comprises: A first H-terminal switching switch, wherein an input end of the first H-terminal switching switch is electrically connected to a high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; an output end of the first H-terminal switching switch is electrically connected to a protection terminal of the capacitance meter; A second H-terminal switching switch, wherein the input end of the second H-terminal switching switch is electrically connected to the high-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second H-terminal switching switch is electrically connected to the high-voltage terminal of the capacitance meter through a first shielding net; A third H-terminal switching switch, wherein the input end of the third H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third H-terminal switching switch is electrically connected to the high current terminal of the capacitance meter through a second shielding net.

4. The multi-channel test circuit for MLCC capacitors according to claim 3, characterized in that: The L-end switching unit comprises: A first L-terminal switching switch, wherein an input end of the first L-terminal switching switch is electrically connected to a low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; an output end of the first L-terminal switching switch is electrically connected to a protection terminal of the capacitance meter; A second L-terminal switching switch, wherein the input end of the second L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the second L-terminal switching switch is electrically connected to the low voltage terminal of the capacitance meter through a third shielding net; A third L-terminal switching switch, wherein the input end of the third L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test, and is electrically connected to one end of the corresponding clamping protection TVS diode; the output end of the third L-terminal switching switch is electrically connected to the low-current terminal of the capacitance meter through a fourth shielding net.

5. The multi-channel test circuit for MLCC capacitors according to claim 2, characterized in that: The clamping protection circuit includes: a first clamping protection TVS diode and a second clamping protection TVS diode, the first clamping protection TVS diode and the second clamping protection TVS diode both correspond to the switching unit one by one; one end of the first clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the first clamping protection TVS diode is electrically connected to the protection terminal of the capacitance meter; one end of the second clamping protection TVS diode is electrically connected to the input end of the corresponding switching unit, and the other end of the second clamping protection TVS diode is electrically connected to the protection terminal of the capacitance meter; The H-end switching unit comprises: A fourth H-terminal switching switch, wherein the input end of the fourth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through a fifth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth H-terminal switching switch is electrically connected to the protection terminal of the capacitance meter; A fifth H-terminal switching switch, wherein the input end of the fifth H-terminal switching switch is electrically connected to the high-level end of the corresponding MLCC capacitor under test through a sixth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth H-terminal switching switch is electrically connected to the high-voltage terminal of the capacitance meter through a seventh shielding net; A sixth H-terminal switching switch, wherein the input end of the sixth H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through an eighth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth H-terminal switching switch is electrically connected to the high current terminal of the capacitance meter through a ninth shielding net; A seventh H-terminal switching switch, wherein the input end of the seventh H-terminal switching switch is electrically connected to the high level end of the corresponding MLCC capacitor under test through the tenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh H-terminal switching switch is electrically connected to the protection terminal of the capacitance meter.

6. The multi-channel test circuit for MLCC capacitors according to claim 5, characterized in that: The L-end switching unit comprises: A fourth L-terminal switching switch, wherein the input end of the fourth L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through the eleventh shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fourth L-terminal switching switch is electrically connected to the protection terminal of the capacitance meter; A fifth L-end switching switch, wherein the input end of the fifth L-end switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through a twelfth shielding net, and is electrically connected to one end of the corresponding first clamping protection TVS diode; the output end of the fifth L-end switching switch is electrically connected to the low voltage terminal of the capacitance meter through a thirteenth shielding net; a sixth L-terminal switching switch, wherein the input end of the sixth L-terminal switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through a fourteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the sixth L-terminal switching switch is electrically connected to the low-current terminal of the capacitance meter through a fifteenth shielding net; A seventh L-end switching switch, wherein the input end of the seventh L-end switching switch is electrically connected to the low-level end of the corresponding MLCC capacitor under test through a sixteenth shielding net, and is electrically connected to one end of the corresponding second clamping protection TVS diode; the output end of the seventh L-end switching switch is electrically connected to the protection terminal of the capacitance meter.

7. The multi-channel test circuit for MLCC capacitors according to any one of claims 3 or 4, characterized in that: The switching unit also includes: A first drive circuit, wherein one end of the first drive circuit is electrically connected to the control unit, and the other end of the first drive circuit is electrically connected to the control end of the third H-end switch or the third L-end switch; the other end of the first drive circuit is also electrically connected to the control end of the second H-end switch or the second L-end switch; A first reverse circuit, one end of the first reverse circuit is electrically connected to the other end of the first drive circuit, and the other end of the first reverse circuit is electrically connected to the control end of the third H-end switching switch or the third L-end switching switch.

8. The multi-channel test circuit for MLCC capacitors according to any one of claims 5 or 6, characterized in that: The switching unit also includes: A second drive circuit, wherein one end of the second drive circuit is electrically connected to the control unit, and the other end of the second drive circuit is electrically connected to the control end of the fifth H-end switch or the fifth L-end switch; the other end of the second drive circuit is also electrically connected to the control end of the sixth H-end switch or the sixth L-end switch; A second reverse circuit, one end of the second reverse circuit is electrically connected to the other end of the second drive circuit, and the other end of the second reverse circuit is electrically connected to the control end of the fourth H-end switching switch or the fourth L-end switching switch; the other end of the second reverse circuit is also electrically connected to the control end of the seventh H-end switching switch or the seventh L-end switching switch.

9. A multi-channel testing method for MLCC capacitors, characterized in that: include: When the host computer does not output a trigger signal to the control unit, the control unit outputs a first control signal to the switching module, and the switching module connects the MLCC capacitor under test to the clamping protection circuit; When the host computer outputs a trigger signal to the control unit, the control unit determines that the test is allowed to start; When the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal, and performs the test; When the MLCC capacitors under test in all channels are tested, the control unit changes the level of the trigger signal to indicate that the test is completed.

10. The multi-channel testing method for MLCC capacitors according to claim 9, characterized in that: When the test starts, the control unit outputs a second control signal to the switching module according to a preset timing, and the switching module sequentially connects the MLCC capacitors under test of different channels to the capacitance meter according to the second control signal and performs the test, including: When the test starts, the control unit outputs a high-level control signal to the corresponding switching unit according to the preset timing, and the corresponding switching unit connects the corresponding MLCC capacitor under test to the capacitance meter and disconnects the corresponding clamping protection circuit to perform a capacitance parameter test of the corresponding MLCC capacitor under test; When the corresponding MLCC capacitor under test completes the test, the control unit outputs a low-level control signal to the corresponding switching unit, and the corresponding switching unit disconnects the corresponding MLCC capacitor under test from the capacitance meter and connects with the corresponding clamping protection circuit to form a discharge loop.

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