Current sampling and amplifying circuit and component-level power electronic device

Abstract

The invention discloses a current sampling and amplifying circuit and a component-level power electronic device. The current sampling and amplifying circuit comprises a current amplifying module used for amplifying a current signal output by an external circuit to obtain an amplified current signal; the input end of the sampling module is electrically connected with the current amplification module, and the sampling module is used for converting the amplified current signal into a voltage signal; the first input end of the differential signal obtaining module is electrically connected with the input end of the sampling module, the second input end of the differential signal obtaining module is electrically connected with the output end of the sampling module, and the differential signal obtaining module is used for obtaining a differential signal according to the voltage signal of the input end of the sampling module and the voltage signal of the output end of the sampling module; and the differential amplification module is used for amplifying the differential signal. The current sampling and amplifying circuit provided by the embodiment of the invention can effectively avoid the problem of common-mode interference.

Description

A current sampling amplifier circuit and a component-level power electronic device Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a current sampling amplifier circuit and a component-level power electronic device. Background Technology

[0002] Current sampling amplifier circuits are widely used in various electronic testing equipment, industrial control devices and other fields.

[0003] Existing current sampling circuits generally employ a "shunt resistor + single-ended operational amplifier" structure. However, because the voltage drop across the shunt resistor is inconsistent with the ground potential, common-mode noise is introduced into the measurement signal. In other words, existing current sampling circuits suffer from significant common-mode interference. Summary of the Invention

[0004] This invention provides a current sampling amplifier circuit and a component-level power electronic device to solve the problem of high common-mode interference in current sampling amplifier circuits.

[0005] According to one aspect of the present invention, a current sampling amplifier circuit is provided, the current sampling amplifier circuit comprising:

[0006] The current amplification module is electrically connected to the output terminal of the external circuit and is used to convert the current signal output by the external circuit into an amplified current signal.

[0007] A sampling module, wherein the input terminal of the sampling module is electrically connected to the current amplification module, and the output terminal of the sampling module is electrically connected to the input terminal of the external circuit, is used to convert the amplified current signal into a voltage signal;

[0008] A differential signal acquisition module, wherein the first input terminal of the differential signal acquisition module is electrically connected to the input terminal of the sampling module, and the second input terminal of the differential signal acquisition module is electrically connected to the output terminal of the sampling module, for obtaining a differential signal based on the voltage signal at the input terminal of the sampling module and the voltage signal at the output terminal of the sampling module;

[0009] A differential amplifier module, wherein the first input terminal of the differential amplifier module is electrically connected to the first output terminal of the differential signal acquisition module, and the second input terminal of the differential amplifier module is electrically connected to the second output terminal of the differential signal acquisition module, is used to amplify the differential signal.

[0010] Optionally, the current sampling amplification circuit further includes: a mode switching module;

[0011] The first output terminal of the mode switching module is electrically connected to the first control terminal of the current amplification module, and the second output terminal of the mode switching module is electrically connected to the second control terminal of the current amplification module, for generating a mode switching signal according to the control signal;

[0012] The current amplification module switches its operating mode according to the mode switching signal;

[0013] The operating modes include low current sampling mode and high current sampling mode.

[0014] Optionally, the current amplification module includes:

[0015] The first current amplification unit has its control terminal electrically connected to the first output terminal of the mode switching module, its input terminal electrically connected to the output terminal of the external circuit, and its output terminal electrically connected to the sampling module. It is used to turn on in the high current sampling mode to amplify the input current signal and obtain a first amplified current signal.

[0016] The second current amplification unit has its control terminal electrically connected to the second output terminal of the mode switching module, its input terminal electrically connected to the output terminal of the external circuit, and its output terminal electrically connected to the sampling module. It is used to turn on in the low current sampling mode to obtain the second amplified current signal.

[0017] The amplified current signal includes the first amplified current signal and the second amplified current signal.

[0018] Optionally, the first current amplification unit includes a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor;

[0019] The control terminals of the first switch, the second switch, the third switch, and the fourth switch are all electrically connected to the first output terminal of the mode switching module. The first switch and the third switch are both connected to a first current signal, and the second switch and the fourth switch are both connected to a second current signal. The output terminals of the first switch, the second switch, the third switch, and the fourth switch are all electrically connected to the input terminal of the sampling module.

[0020] The second current amplification unit includes a fifth switching transistor. The control terminal of the fifth switching transistor is electrically connected to the second output terminal of the mode switching module. The input terminal of the fifth switching transistor is connected to the first current signal and the second current signal. The output terminal of the fifth switching transistor is electrically connected to the input terminal of the sampling module.

[0021] The current signal includes the first current signal and the second current signal.

[0022] Optionally, the sampling module includes:

[0023] The first sampling unit has its input terminal electrically connected to the output terminal of the first current amplification unit, and its output terminal electrically connected to the input terminal of the external circuit, for converting the first current amplification signal into a first voltage signal.

[0024] The second sampling unit has its input terminal electrically connected to the output terminal of the second current amplification unit, and its output terminal electrically connected to the input terminal of the external circuit, for converting the second current amplification signal into a second voltage signal.

[0025] The voltage signal includes the first voltage signal and the second voltage signal.

[0026] Optionally, the first sampling unit includes a first resistor, which is connected between the output terminal of the first current amplification unit and the input terminal of the external circuit.

[0027] The second sampling unit includes a second resistor, which is connected between the output terminal of the second current amplification unit and the input terminal of the external circuit.

[0028] The resistance value of the first resistor is less than the resistance value of the second resistor.

[0029] Optionally, the first resistor and / or the second resistor are low temperature coefficient alloy resistors.

[0030] Optionally, the differential signal acquisition module includes:

[0031] A first switching unit, wherein a first input terminal of the first switching unit is electrically connected to the input terminal of the first sampling unit, a second input terminal of the first switching unit is electrically connected to the input terminal of the second sampling unit, and an output terminal of the first switching unit is electrically connected to the first input terminal of the differential amplifier module, is used to obtain the first input voltage of the input terminal of the first sampling unit in the high current sampling mode or to obtain the second input voltage of the input terminal of the second sampling unit in the low current sampling mode;

[0032] The second switching unit has a first input terminal electrically connected to the output terminal of the first sampling unit, a second input terminal electrically connected to the output terminal of the second sampling unit, and an output terminal electrically connected to the second input terminal of the differential amplifier module. It is used to obtain the first output voltage of the output terminal of the first sampling unit in the high current sampling mode or to obtain the second output voltage of the output terminal of the second sampling unit in the low current sampling mode.

[0033] The differential signal is the difference between the first input voltage and the first output voltage or the difference between the second input voltage and the second output voltage.

[0034] Optionally, the differential amplifier module includes an operational amplifier unit, a third resistor, and a first capacitor;

[0035] The first input terminal of the operational amplifier unit is electrically connected to the first output terminal of the differential signal acquisition module, and the second input terminal of the operational amplifier unit is electrically connected to the second output terminal of the differential signal acquisition module, for amplifying the differential signal by a proportional coefficient;

[0036] The first capacitor is electrically connected between the third input terminal and the ground terminal of the operational amplifier unit, the third resistor is electrically connected between the third input terminal and the fourth input terminal of the operational amplifier unit, and the third input terminal of the operational amplifier unit is electrically connected to the first DC voltage source.

[0037] According to another aspect of the present invention, a component-level power electronic device is provided, comprising: the current sampling amplifier circuit described in any embodiment of the present invention.

[0038] The technical solution provided in this invention uses a current amplification module to initially amplify the received current signal, then a sampling module converts the current signal into a voltage signal. A differential signal acquisition module then acquires the voltage difference between the input and output terminals of the sampling module to obtain a differential signal. Finally, this differential signal is further amplified by the differential amplification module. Because the differential signal has a high common-mode rejection ratio, it can significantly and effectively suppress noise, greatly improving the sampling accuracy, signal integrity, and anti-interference capability of the current sampling amplification circuit. In other words, the current sampling amplification circuit provided in this invention can effectively avoid the problem of common-mode interference.

[0039] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 is a schematic diagram of a current sampling amplifier circuit provided in an embodiment of the present invention;

[0042] Figure 2 is a schematic diagram of another current sampling amplifier circuit provided in an embodiment of the present invention;

[0043] Figure 3 is a schematic diagram of another current sampling amplifier circuit provided in an embodiment of the present invention. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0046] Figure 1 is a schematic diagram of a current sampling amplifier circuit provided in an embodiment of the present invention. This embodiment is applicable to sampling test current. As shown in Figure 1, the current sampling amplifier circuit 100 includes:

[0047] The current amplification module 110 is electrically connected to the output terminal 210 of the external circuit and is used to convert the current signal output by the external circuit into an amplified current signal.

[0048] The sampling module 120 has its input terminal electrically connected to the current amplification module 110 and its output terminal electrically connected to the input terminal 220 of the external circuit. It is used to convert the amplified current signal into a voltage signal.

[0049] The differential signal acquisition module 130 has its first input terminal electrically connected to the input terminal of the sampling module 120, and its second input terminal electrically connected to the output terminal of the sampling module 120. It is used to obtain a differential signal based on the voltage signal at the input terminal and the voltage signal at the output terminal of the sampling module 120.

[0050] The differential amplifier module 140 has its first input terminal electrically connected to the first output terminal of the differential signal acquisition module 130, and its second input terminal electrically connected to the second output terminal of the differential signal acquisition module 130, for amplifying the differential signal.

[0051] Specifically, the current amplification module 110 receives the current signal output from the external circuit and amplifies it using devices such as transistors or operational amplifiers to obtain an amplified current signal. The sampling module 120 converts this amplified current signal into a voltage signal. Simultaneously, the sampling module 120 is connected to the external circuit without affecting its overall normal operation. The differential signal acquisition module 130 compares the voltages at the input and output terminals of the sampling module 120 to extract the difference, thus obtaining a differential signal. Because the differential signal has a high common-mode rejection ratio (CMRR), it can attenuate common-mode interference (such as power supply noise or environmental interference) to an extremely low level. For example, when the common-mode voltage is within the common-mode range of a conventional line and the CMRR is high, the residual common-mode interference signal at the output terminal is much smaller than the amplitude of the effective sampled signal. In this way, the differential signal acquisition module 130 can effectively suppress noise, significantly improving the sampling accuracy and signal integrity of the current sampling amplification circuit 100. The differential amplifier module 140 further amplifies the differential signal to improve its signal-to-noise ratio and signal amplitude, facilitating subsequent precise analysis of the differential signal's characteristics.

[0052] The technical solution provided in this embodiment of the invention uses a current amplification module 110 to initially amplify the received current signal, then a sampling module 120 to convert the current signal into a voltage signal, a differential signal acquisition module 130 to acquire the voltage difference between the input and output terminals of the sampling module 120 to obtain a differential signal, and finally amplifies the differential signal further using a differential amplification module 140. Because the differential signal has a high common-mode rejection ratio, it can significantly and effectively suppress noise, greatly improving the sampling accuracy, signal integrity, and anti-interference capability of the current sampling amplification circuit 100. In other words, the current sampling amplification circuit 100 provided in this embodiment of the invention can effectively avoid the problem of common-mode interference.

[0053] Figure 2 is a schematic diagram of another current sampling amplifier circuit provided in an embodiment of the present invention. Optionally, based on the above embodiments, as shown in Figure 2, the current sampling amplifier circuit 100 further includes a mode switching module 150. The first output terminal of the mode switching module 150 is electrically connected to the first control terminal of the current amplification module 110, and the second output terminal of the mode switching module 150 is electrically connected to the second control terminal of the current amplification module 110, used to generate a mode switching signal according to a control signal. The current amplification module 110 switches its operating mode according to the mode switching signal; wherein the operating mode includes a small current sampling mode and a large current sampling mode.

[0054] Specifically, the mode switching module 150 can issue a mode switching signal, which is used to dynamically switch the operating mode of the current amplification module 110 to adapt to different ranges of input current signals, thereby improving the dynamic range and accuracy of the circuit. For example, when switching to the high current sampling mode, the current amplification module 110 amplifies the current output by the external circuit, thereby providing a high current to the sampling module 120; when switching to the low current sampling mode, the current amplification module 110 does not change the output current of the external circuit, thereby providing a low current to the sampling module 120.

[0055] Based on the above embodiments, optionally, referring to FIG2, the current amplification module 110 includes:

[0056] The first current amplification unit 111 has its control terminal electrically connected to the first output terminal of the mode switching module 150, its input terminal electrically connected to the output terminal 210 of the external circuit, and its output terminal electrically connected to the sampling module 120. It is used to conduct in the high current sampling mode to amplify the input current signal and obtain the first amplified current signal.

[0057] The second current amplification unit 112 has its control terminal electrically connected to the second output terminal of the mode switching module 150, its input terminal electrically connected to the output terminal 210 of the external circuit, and its output terminal electrically connected to the sampling module 120. It is used to conduct in the small current sampling mode to obtain the second amplified current signal.

[0058] The amplified current signal includes a first amplified current signal and a second amplified current signal.

[0059] Specifically, the first current amplification unit 111 can be turned on in high current sampling mode and amplify the small current signal to output a first amplified current signal. The second current amplification unit 112 can be turned on in low current sampling mode and output a second amplified current signal.

[0060] In this embodiment of the invention, in the high-current sampling mode, the first current amplification unit 111 amplifies the current signal to obtain a large current, i.e., the first amplified current. In this mode, the resistance value used for sampling is relatively small. In the low-current sampling mode, the second current amplification unit 112 does not amplify the current signal; it simply conducts to obtain the second amplified current. In this mode, the resistance value used for sampling is relatively large. Thus, regardless of whether it is the low-current sampling mode or the high-current sampling mode, the voltage value converted by the sampling module is within a stable range.

[0061] The technical solution of this invention uses a mode switching module 150 to switch the operating mode of the current amplification module 110, enabling the current amplification module 110 to switch current amplification methods according to the sampling mode, thereby significantly improving the detection accuracy and dynamic range of the system. Furthermore, due to the presence of the mode switching module 150, only one operational amplifier is needed to adapt to different current levels when processing differential signals. Compared to traditional solutions, the technical solution of this invention saves one operational amplifier device and reduces the number of supporting resistors and capacitors, which not only significantly reduces hardware costs but also optimizes the PCB layout area and improves the system's integration and cost-effectiveness.

[0062] Figure 3 is a schematic diagram of another current sampling amplifier circuit provided in an embodiment of the present invention. As shown in Figure 3, the first current amplification unit 111 includes a first switch 113, a second switch 114, a third switch 115, and a fourth switch 116.

[0063] The control terminals of the first switch transistor 113, the second switch transistor 114, the third switch transistor 115, and the fourth switch transistor 116 are all electrically connected to the first output terminal of the mode switching module 150. The first switch transistor 113 and the third switch transistor 115 are both connected to the first current signal, and the second switch transistor 114 and the fourth switch transistor 116 are both connected to the second current signal. The output terminals of the first switch transistor 113, the second switch transistor 114, the third switch transistor 115, and the fourth switch transistor 116 are all electrically connected to the input terminal of the sampling module 120.

[0064] The second current amplification unit 112 includes a fifth switch 117. The control terminal of the fifth switch 117 is electrically connected to the second output terminal of the mode switching module 150. The input terminal of the fifth switch 117 is connected to the first current signal and the second current signal. The output terminal of the fifth switch 117 is electrically connected to the input terminal of the sampling module 120.

[0065] The current signal includes a first current signal and a second current signal.

[0066] Specifically, as shown in Figure 3, the external circuit may include: a controller 101, an isolation communication module 102, a digital-to-analog converter 103, an electronic switch 104, a constant current control module 105, a first current generation module 106, a second current generation module 107, a current comparison module 108, a measurement range switching module 109, an output polarity switching H-bridge 1010, an isolation drive module 1011, an isolation power supply module 1012, and a protection tube voltage drop detection and comparison module 1013.

[0067] In this embodiment of the invention, when the operating mode is high-current sampling mode, the first switch 113, the second switch 114, the third switch 115, and the fourth switch 116 simultaneously amplify the input current signal, thereby increasing the sampling current of the sampling module 120. When the operating mode is low-current sampling mode, the fifth switch 117 is turned on, allowing the sampling module 120 to receive a low current.

[0068] Based on the above embodiments, referring to FIG2, optionally, the sampling module 120 includes:

[0069] The first sampling unit 121 has its input terminal electrically connected to the output terminal of the first current amplification unit 111, and its output terminal electrically connected to the input terminal of an external circuit, for converting the first current amplification signal into a first voltage signal.

[0070] The second sampling unit 122 has its input terminal electrically connected to the output terminal of the second current amplification unit 112, and its output terminal electrically connected to the input terminal of an external circuit, for converting the second current amplification signal into a second voltage signal.

[0071] The voltage signal includes a first voltage signal and a second voltage signal.

[0072] Specifically, in the low-current discharge mode, the first sampling unit 121 converts the first current amplification signal output by the first current amplification unit 111 into a first voltage signal. In the high-current discharge mode, the second sampling unit 122 converts the second current amplification signal output by the second current amplification unit 112 into a second voltage signal.

[0073] Based on the above embodiments, and continuing to refer to FIG3, optionally, the first sampling unit 121 includes a first resistor 123, which is connected between the output terminal of the first current amplification unit 111 and the input terminal of the external circuit. The second sampling unit 122 includes a second resistor 124, which is connected between the output terminal of the second current amplification unit 112 and the input terminal of the external circuit. The resistance value of the first resistor 123 is less than the resistance value of the second resistor 124.

[0074] Specifically, the first resistor 123 has a smaller resistance value, which enables it to convert the large current after current amplification into a lower voltage in high-current sampling mode. The second resistor 124 has a larger resistance value, which enables it to convert the small current into a higher voltage in low-current sampling mode. This allows the voltage value subsequently input to the differential amplifier module 140 to be stabilized within a fixed range.

[0075] In the above embodiments, optionally, the first resistor 123 is a low-temperature coefficient alloy resistor. Optionally, the second resistor 124 is a low-temperature coefficient alloy resistor.

[0076] Specifically, the temperature coefficient of low-temperature-coefficient alloy resistors is much lower than that of ordinary metal film resistors, which can reduce temperature drift. Through device-level low-temperature-coefficient design, the technical solution of this invention can control the impact of temperature changes on the sampled values ​​within ±0.05%, thus meeting the requirements of wide-temperature-range scenarios.

[0077] Optionally, the first resistor 123 can also be a low-temperature coefficient alloy resistor, which must meet the requirements of resistance accuracy less than or equal to 1% and temperature coefficient less than 100ppm / ℃. The second resistor 124 can also be a low-temperature coefficient alloy resistor, which must meet the requirements of resistance accuracy less than or equal to 1% and temperature coefficient less than 100ppm / ℃.

[0078] Based on the above embodiments, referring to FIG2, optionally, the differential signal acquisition module 130 includes:

[0079] The first switching unit 131 has its first input terminal electrically connected to the input terminal of the first sampling unit 121, its second input terminal electrically connected to the input terminal of the second sampling unit 122, and its output terminal electrically connected to the first input terminal of the differential amplifier module 140. It is used to obtain the first input voltage of the input terminal of the first sampling unit 121 in high current sampling mode or to obtain the second input voltage of the input terminal of the second sampling unit 122 in low current sampling mode.

[0080] The second switching unit 132 has its first input terminal electrically connected to the output terminal of the first sampling unit 121, its second input terminal electrically connected to the output terminal of the second sampling unit 122, and its output terminal electrically connected to the second input terminal of the differential amplifier module 140. It is used to acquire the first output voltage of the first sampling unit 121 in high-current sampling mode or the second output voltage of the second sampling unit 122 in low-current sampling mode. The differential signal is the difference between the first input voltage and the first output voltage, or the difference between the second input voltage and the second output voltage.

[0081] Specifically, the first switching unit 131 is matched with the first resistor 123, and the second switching unit 132 is matched with the second resistor 124. In high-current sampling mode, the first switching unit 131 transmits the voltage at the input terminal of the first resistor 123 to the first input terminal of the operational amplifier unit of the operational amplifier module, and transmits the voltage at the output terminal of the first resistor 123 to the second input terminal of the operational amplifier unit of the operational amplifier module to obtain a differential signal. In low-current sampling mode, the first switching unit 131 transmits the voltage at the input terminal of the second resistor 124 to the first input terminal of the operational amplifier unit of the operational amplifier module, and transmits the voltage at the output terminal of the second resistor 124 to the second input terminal of the operational amplifier unit of the operational amplifier module to obtain a differential signal.

[0082] In this embodiment of the invention, the first switching unit 131 and the second switching unit 132 may include analog switching devices. These analog switching devices need to meet requirements such as low on-resistance and high switching speed to adapt to circuit bandwidth.

[0083] Based on the above embodiments, and continuing to refer to FIG3, optionally, the differential amplifier module 140 includes an operational amplifier unit 141, a third resistor 142, and a first capacitor 143. The first input terminal of the operational amplifier unit 141 is electrically connected to the first output terminal of the differential signal acquisition module 130, and the second input terminal of the operational amplifier unit 141 is electrically connected to the second output terminal of the differential signal acquisition module 130, for amplifying the differential signal by a proportional coefficient. The first capacitor 143 is electrically connected between the third input terminal and the ground terminal of the operational amplifier unit 141, the third resistor 142 is electrically connected between the third input terminal and the fourth input terminal of the operational amplifier unit 141, and the third input terminal of the operational amplifier unit 141 is electrically connected to a first DC voltage source.

[0084] Specifically, the operational amplifier unit 141 may include a high-precision, low-temperature-drift operational amplifier with a temperature drift significantly lower than that of ordinary operational amplifiers. This suppresses temperature drift, enabling the current sampling amplifier circuit 100 to operate reliably within a temperature range of -40℃ to 85℃. Experimental verification has shown that introducing a high-precision, low-temperature-drift operational amplifier can control the introduced temperature drift error within ±0.05%. Optionally, the operational amplifier unit 141 may also use a high-precision differential operational amplifier of equivalent level, or an instrumentation amplifier with an internally integrated differential amplifier architecture.

[0085] In this embodiment of the invention, the first capacitor 143 can be a surface-mount capacitor with good high-frequency characteristics, and the third resistor 142 can be a resistor with a high resonant frequency, so that the bandwidth of the entire current sampling amplifier circuit 100 is increased to more than 100kHz, which can capture microsecond-level current transients such as pulse charging current.

[0086] The technical solution of this invention, by setting the first resistor 123 and / or the second resistor 124 to be low-temperature coefficient alloy resistors, and by setting the operational amplifier unit 141 to include a high-precision, low-temperature-drift operational amplifier with a temperature drift far lower than that of ordinary operational amplifiers, can suppress temperature drift and increase the temperature range of the current sampling amplifier circuit 100. By setting the first capacitor 143 to be a surface-mount capacitor with good high-frequency characteristics, and the third resistor 142 to be a resistor with a high resonant frequency, the frequency range of the current sampling amplifier circuit 100 can be improved.

[0087] This invention also provides a component-level power electronic device, including: the current sampling amplification circuit provided in any of the above embodiments, having the corresponding functional modules and beneficial effects of the current sampling circuit.

[0088] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0089] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A current sampling amplifier circuit, characterized in that, The current sampling amplification circuit includes: a current amplification module electrically connected to the output terminal of an external circuit, used to convert the current signal output by the external circuit into an amplified current signal; a sampling module, the input terminal of the sampling module electrically connected to the current amplification module, and the output terminal of the sampling module electrically connected to the input terminal of the external circuit, used to convert the amplified current signal into a voltage signal; a differential signal acquisition module, the first input terminal of the differential signal acquisition module electrically connected to the input terminal of the sampling module, and the second input terminal of the differential signal acquisition module electrically connected to the output terminal of the sampling module, used to obtain a differential signal based on the voltage signal at the input terminal and the voltage signal at the output terminal of the sampling module; and a differential amplification module, the first input terminal of the differential amplification module electrically connected to the first output terminal of the differential signal acquisition module, and the second input terminal of the differential amplification module electrically connected to the second output terminal of the differential signal acquisition module, used to amplify the differential signal.

2. The current sampling amplifier circuit according to claim 1, characterized in that, The current sampling amplification circuit further includes: a mode switching module; the first output terminal of the mode switching module is electrically connected to the first control terminal of the current amplification module, and the second output terminal of the mode switching module is electrically connected to the second control terminal of the current amplification module, for generating a mode switching signal according to the control signal; the current amplification module switches the operating mode according to the mode switching signal; wherein, the operating mode includes a small current sampling mode and a large current sampling mode.

3. The current sampling amplifier circuit according to claim 2, characterized in that, The current amplification module includes: a first current amplification unit, the control terminal of which is electrically connected to the first output terminal of the mode switching module, the input terminal of which is electrically connected to the output terminal of the external circuit, and the output terminal of which is electrically connected to the sampling module, for conducting in the high-current sampling mode to amplify the input current signal to obtain a first amplified current signal; and a second current amplification unit, the control terminal of which is electrically connected to the second output terminal of the mode switching module, the input terminal of which is electrically connected to the output terminal of the external circuit, and the output terminal of which is electrically connected to the sampling module, for conducting in the low-current sampling mode to obtain a second amplified current signal; wherein the amplified current signal includes the first amplified current signal and the second amplified current signal.

4. The current sampling amplifier circuit according to claim 3, characterized in that, The first current amplification unit includes a first switch, a second switch, a third switch, and a fourth switch. The control terminals of the first, second, third, and fourth switches are all electrically connected to the first output terminal of the mode switching module. The first and third switches are each connected to a first current signal, and the second and fourth switches are each connected to a second current signal. The output terminals of the first, second, third, and fourth switches are all electrically connected to the input terminal of the sampling module. The second current amplification unit includes a fifth switch. The control terminal of the fifth switch is electrically connected to the second output terminal of the mode switching module. The input terminal of the fifth switch is connected to both the first and second current signals, and the output terminal of the fifth switch is electrically connected to the input terminal of the sampling module. The current signals include both the first and second current signals.

5. The current sampling amplifier circuit according to claim 3, characterized in that, The sampling module includes: a first sampling unit, the input terminal of which is electrically connected to the output terminal of the first current amplification unit, and the output terminal of which is electrically connected to the input terminal of the external circuit, for converting the first current amplification signal into a first voltage signal; and a second sampling unit, the input terminal of which is electrically connected to the output terminal of the second current amplification unit, and the output terminal of which is electrically connected to the input terminal of the external circuit, for converting the second current amplification signal into a second voltage signal; wherein the voltage signal includes the first voltage signal and the second voltage signal.

6. The current sampling amplifier circuit according to claim 5, characterized in that, The first sampling unit includes a first resistor connected between the output terminal of the first current amplification unit and the input terminal of the external circuit; the second sampling unit includes a second resistor connected between the output terminal of the second current amplification unit and the input terminal of the external circuit; wherein the resistance value of the first resistor is less than the resistance value of the second resistor.

7. The current sampling amplifier circuit according to claim 6, characterized in that, The first resistor and / or the second resistor are low temperature coefficient alloy resistors.

8. The current sampling amplifier circuit according to claim 5, characterized in that, The differential signal acquisition module includes: a first switching unit, wherein a first input terminal of the first switching unit is electrically connected to the input terminal of the first sampling unit, a second input terminal of the first switching unit is electrically connected to the input terminal of the second sampling unit, and an output terminal of the first switching unit is electrically connected to the first input terminal of the differential amplification module, for acquiring a first input voltage of the input terminal of the first sampling unit in the high-current sampling mode or acquiring a second input voltage of the input terminal of the second sampling unit in the low-current sampling mode; and a second switching unit, wherein a first input terminal of the second switching unit is electrically connected to the output terminal of the first sampling unit, a second input terminal of the second switching unit is electrically connected to the output terminal of the second sampling unit, and an output terminal of the second switching unit is electrically connected to the second input terminal of the differential amplification module, for acquiring a first output voltage of the output terminal of the first sampling unit in the high-current sampling mode or acquiring a second output voltage of the output terminal of the second sampling unit in the low-current sampling mode; wherein the differential signal is the difference between the first input voltage and the first output voltage or the difference between the second input voltage and the second output voltage.

9. The current sampling amplifier circuit according to claim 1, characterized in that, The differential amplifier module includes an operational amplifier unit, a third resistor, and a first capacitor. The first input terminal of the operational amplifier unit is electrically connected to the first output terminal of the differential signal acquisition module, and the second input terminal of the operational amplifier unit is electrically connected to the second output terminal of the differential signal acquisition module, for amplifying the differential signal by a proportional coefficient. The first capacitor is electrically connected between the third input terminal of the operational amplifier unit and the ground terminal, the third resistor is electrically connected between the third input terminal and the fourth input terminal of the operational amplifier unit, and the third input terminal of the operational amplifier unit is electrically connected to a first DC voltage source.

10. A component-level power electronic device, characterized in that, include: The current sampling amplifier circuit as described in any one of claims 1-9.

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