Hundred-ampere-grade multi-probe transmission delay calibration device

Abstract

The invention discloses a hundred-ampere-level multi-probe transmission delay calibration device, and relates to the technical field of power semiconductor test methods and equipments.The hundred-ampere-level multi-probe transmission delay calibration device comprises a resistive load switch module, a driving module and a transmission module, and the resistive load switch module is adaptively connected with a calibration object through the transmission module; the resistive load switch module comprises a switch device Q1, and the switch device Q1 is adaptively connected with the driving module; the driving module is used for driving the switch device Q1 to enable the resistive load switch module to generate a calibration signal, and the calibration signal is transmitted to the calibration object through the transmission module. The transmission delay calibration device supports calibration signal output of a current probe at a hundred-ampere level, and is adaptive to various probe types.

Description

Technical Field

[0001] The invention relates to the technical field of power semiconductor testing methods and equipment, and in particular to a multi-probe transmission delay calibration device of a hundred-ampere level. Background Art

[0002] The transmission delay calibration device is mainly used in the field of power electronics (power supply) analysis and dynamic characteristics measurement and analysis of high-speed power devices. The purpose is to use the high current and high voltage synchronous electrical waveforms (time domain signals) generated by the device to adjust various voltage probes and current probes at the signal acquisition end of the oscilloscope to keep the transmission time of each probe consistent, so as to obtain accurate measurement results.

[0003] The transmission delay calibration devices currently on the market mainly have the following problems:

[0004] (1) The excitation signals of the voltage and current probes are relatively low, usually reaching a current range of only 0.1A to 1A, and a voltage range of only about 5 to 10V, which is much lower than the actual measurement current and voltage range of the calibration object (1A to 100A, 10V to 1000V). This results in a large delay error between the probes of the calibration object even with this type of calibration device. Therefore, the calibration effect of various probes in actual use scenarios is very small and the reference value is limited. The achievable speed of some devices is also relatively slow (reaching more than 100ns), which affects the effect of delay calibration.

[0005] (2) The calibration device is designed with fewer measurement formats available (mainly probes), and is not suitable for measuring high-speed power devices or modules. Usually, this type of measurement uses a high-speed coaxial current shunt resistor, a high-voltage closed-end Rogowski coil, an optically isolated voltage probe with an MMXC interface at the front end, a high-voltage differential probe with a BNC interface at the front end, etc. However, the delay calibration devices currently available on the market cannot meet or can only partially meet the above measurement formats. In most cases, this device is used to measure high voltage and current levels. If the delay calibration operation cannot be performed on the mainstream probe, the measurement results will be seriously deviated, affecting the accuracy and validity of the data.

[0006] (3) The calibration device can accommodate a small number of probes, which means that each calibration is usually not enough to accommodate the corresponding number of probes involved in the experiment. At the same time, the connection and assembly is cumbersome and the flexibility is insufficient, resulting in a long preparation time and calibration time for the calibration experiment, usually ranging from 10 to 20 minutes, which is very inefficient. Summary of the invention

[0007] In view of the above problems and technical requirements, the inventors have proposed a multi-probe transmission delay calibration device at the hundred-ampere level.

[0008] The technical solution of the present invention is as follows:

[0009] A 100-ampere-level multi-probe transmission delay calibration device comprises a resistive load switch module, a drive module and a transmission module, wherein the resistive load switch module is adaptively connected to a calibration object through the transmission module; the resistive load switch module comprises a switch device Q1, and the switch device Q1 is adaptively connected to the drive module;

[0010] The driving module is used to drive the switch device Q1 to make the resistive load switch module generate a calibration signal, and the calibration signal is transmitted to the calibration object through the transmission module.

[0011] A further technical solution is that the resistive load switch module further includes a film capacitor C1, a load resistor RLoad and a coaxial shunt resistor, one end of the film capacitor C1 is connected to the third electrode of the switch device Q1, the second electrode of the switch device Q1 is connected to the driving module, and the first electrode of the switch device Q1 is electrically connected to one end of the load resistor R Load to form a first connection point;

[0012] The other end of the load resistor R Load is connected to one end of the coaxial shunt resistor, and the other end of the coaxial shunt resistor is connected to the other end of the film capacitor C1 to form a second connection point; both ends of the film capacitor C1 are loaded with a DC power supply voltage.

[0013] A further technical solution is that the load resistor R Load is a non-inductive resistor.

[0014] A further technical solution is that the switch device Q1 includes an N-type MOSFET switch tube.

[0015] A further technical solution is that the transmission module includes a plurality of high-voltage transmission units connected to the first connection point, and a plurality of low-voltage transmission units connected to the second connection point, and the high-voltage transmission units correspond one to one to the low-voltage transmission units.

[0016] Its further technical solution is that any high-voltage transmission unit includes a high-voltage wire and a probe interface connected to a first connection point through the high-voltage wire; any low-voltage transmission unit includes a low-voltage wire and a probe interface connected to a second connection point through the low-voltage wire; the probe interfaces include multiple types.

[0017] A further technical solution is that all high-voltage wires have the same length; and all low-voltage wires have the same length.

[0018] A further technical solution is that the transmission module comprises a Rogowski coil installation section for installing the Rogowski coil, and the Rogowski coil installation section is electrically connected between the first electrode and the first connection point of the switching device Q1.

[0019] A further technical solution is that the driving module includes a digital isolator U1, a gate driver U2, a resistor R4, a resistor R6, a resistor R7, a resistor R8, a capacitor C10, a capacitor C11 and a capacitor C12;

[0020] The output pin of the digital isolator U1 is connected to the input pin of the gate driver U2, and the output pin of the digital isolator U1 is also connected to the first negative power supply voltage through the resistor R4;

[0021] The output pin of the gate driver U2 is connected to the second electrode of the switch device Q1 and one end of the resistor R8 through the resistor R6; the output pin of the gate driver U2 is also connected to the cathode of the TVS tube D3, and the anode of the TVS tube D3 is connected to one end of the resistor R6 and one end of the resistor R8 through the resistor R7;

[0022] The other end of the resistor R8 is connected to the first electrode of the switch device Q1, one end of the capacitor C10, one end of the capacitor C11 and one end of the capacitor C12, and the other end of the capacitor C10, the other end of the capacitor C11 and the other end of the capacitor C12 are connected to the first negative power supply voltage.

[0023] A further technical solution is that the film capacitor C1 is also connected in parallel with a protection resistor.

[0024] The beneficial technical effects of the present invention are:

[0025] (1) It can generate higher voltage and current probe excitation signals, i.e. calibration signals, and the calibration speed is fast. The current range that can be measured by the current probe is in the order of 1A to 100A, and the voltage range that can be measured by the voltage probe is in the order of 10V to 1000V. The calibration speed can reach 10ns, which can achieve good delay calibration effect.

[0026] (2) It can adapt to a variety of excitation signal measurement forms, including high-speed coaxial shunt resistors, 100MHz bandwidth high-voltage closed-end Rogowski coils, optically isolated voltage probes with MMXC interfaces at the front end, high-voltage differential probes with BNC interfaces at the front end, etc., as well as conventional single-tube probes and various floating high / low voltage differential probes.

[0027] (3) Multiple probes of different types can be connected at the same time to fully accommodate the corresponding number of probes involved in the calibration. At the same time, the connection and removal are convenient and fast, with high flexibility, shortening the calibration experiment preparation time and calibration time, which is controlled within 1 to 2 minutes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of an embodiment of a resistive load switch module provided by the present invention.

[0029] Figure 2 It is a schematic diagram of an embodiment of a driving module provided by the present invention.

[0030] Figure 3 The present invention is a schematic diagram of PCB distribution of an embodiment of a transmission delay calibration device. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0032] The present invention provides a multi-probe transmission delay calibration device of 100-ampere level, comprising a resistive load switch module, a drive module and a transmission module, wherein the resistive load switch module is adaptively connected to a calibration object through the transmission module; the resistive load switch module comprises a switch device Q1, and the switch device Q1 is adaptively connected to the drive module;

[0033] The driving module is used to drive the switch device Q1 to make the resistive load switch module generate a calibration signal, and the calibration signal is transmitted to the calibration object through the transmission module.

[0034] Specifically, the resistive load switch module, the driving module and the transmission module are arranged on the PCB, and the driving module drives the high-speed switch device Q1 based on a square pulse signal with a width of about 50ns to 200ns, so that the resistive load switch module generates a calibration signal. The calibration object can be an oscilloscope, and the calibration signal is a synchronous electrical waveform (time domain signal) of high current and high voltage. The transmission module is connected to various current probes and voltage probes of the oscilloscope, and the current probes and voltage probes are correspondingly connected to each signal input channel of the oscilloscope, and the calibration signal is finally transmitted to each signal input channel of the oscilloscope. A channel adjustment function is usually provided inside the oscilloscope, and a signal advance or delay of more than 10ns can be set for each signal input channel. After the synchronous electrical waveform is input to each signal channel of the oscilloscope, the waveforms received by each signal channel are aligned by using the channel adjustment function inside the oscilloscope, and the delay calibration of each probe of the oscilloscope can be completed.

[0035] Further, the resistive load switch module further includes a film capacitor C1, a load resistor R Load and a coaxial shunt resistor, one end of the film capacitor C1 is connected to the third electrode of the switch device Q1, the second electrode of the switch device Q1 is connected to the driving module, and the first electrode of the switch device Q1 is electrically connected to one end of the load resistor R Load to form a first connection point;

[0036] The other end of the load resistor R Load is connected to one end of the coaxial shunt resistor, and the other end of the coaxial shunt resistor is connected to the other end of the film capacitor C1 to form a second connection point; both ends of the film capacitor C1 are loaded with a DC power supply voltage.

[0037] Specifically, the two ends of the film capacitor C1 are connected to the positive terminal and the negative terminal respectively, and are used to access a DC power supply. The DC power supply voltage value can be 100V to 300V. The load resistor R Load is a non-inductive resistor. Non-inductive resistors have low inductance characteristics, which can reduce the impact of inductance on the circuit and are suitable for high-frequency circuits. The first connection point is Figure 1 The second connection point is point a shown in FIG. Figure 1 Point b shown. In this embodiment, the capacitance value of the thin film capacitor C1 can be 20μF, and the switching device Q1 adopts an N-type MOSFET switching tube. For the N-type MOSFET switching tube, the first electrode of the switching device Q1 is the source, the second electrode is the gate, and the third electrode is the drain. The positive electrode of the DC power supply is connected to one end of the thin film capacitor C1 and the drain of the N-type MOSFET switching tube Q1, and the negative electrode of the DC power supply is connected to the other end of the thin film capacitor C1 and one end of the coaxial shunt resistor. In specific implementation, the switching device Q1 can also adopt other power devices with switching functions. The thin film capacitor C1 is also connected in parallel with a protective resistor to provide buffer protection. The protective resistor is a cement resistor with large resistance and power.

[0038] The driving module controls the high-speed switch device Q1 to switch between the on state and the off state. At the moment when the driving module controls the high-speed switch device Q1 to turn on, the current flows through the non-inductive load resistor R Load and the shunt resistor in sequence, and at the same time, a synchronous voltage V is generated between the first connection point and the second connection point of the load resistor R Load and the shunt resistor. R The synchronous electrical waveform can be obtained by continuously measuring the current in the loop where the load resistor R Load is located and the voltage between the first connection point and the second connection point.

[0039] Furthermore, to facilitate the connection of various types of voltage probes, the transmission module includes multiple high-voltage transmission units connected to the first connection point, and multiple low-voltage transmission units connected to the second connection point, and the high-voltage transmission units correspond one-to-one to the low-voltage transmission units.

[0040] Specifically, any high-voltage transmission unit includes a high-voltage wire and a probe interface connected to a first connection point through the high-voltage wire; any low-voltage transmission unit includes a low-voltage wire and a probe interface connected to a second connection point through the low-voltage wire.

[0041] When collecting the voltage of the first connection point, multiple voltage probes can be connected to the first connection point in parallel through different probe interfaces; when collecting the voltage of the second connection point, multiple voltage probes can be connected to the second connection point in parallel through different probe interfaces. The probe interface can be in a variety of interface forms, and multiple probe interfaces of each interface form can be set to simultaneously meet the calibration of multiple probes of the same form. The probe interface can support the connection of conventional single-tube probes and various floating high / low voltage differential probes, optically isolated voltage probes with MMXC interface at the front end, and high-voltage differential probes with BNC interface at the front end, etc.

[0042] When collecting the voltage between the first connection point and the second connection point, a high voltage signal needs to be collected through a high voltage transmission unit, and a low voltage signal needs to be collected through a low voltage transmission unit at the same time. In order to make the high voltage signals collected by all voltage probes the same and the low voltage signals collected by all voltage probes the same, the circuit layout design on the PCB needs to make the lengths of all high voltage wires the same and the lengths of all low voltage wires the same.

[0043] Furthermore, the transmission module includes a Rogowski coil installation section for installing the Rogowski coil, and the Rogowski coil installation section is electrically connected between the first electrode and the first connection point of the switching device Q1.

[0044] Specifically, the Rogowski coil installation section is a connection conductor reserved between the first electrode and the first connection point of the switching device Q1 for the Rogowski coil to surround. The Rogowski coil measures the current in the loop where the load resistor RLoad is located by surrounding the connection conductor and transmits it to the current probe.

[0045] Further, the driving module includes a digital isolator U1, a gate driver U2, a resistor R4, a resistor R6, a resistor R7, a resistor R8, a TVS tube D3, a capacitor C10, a capacitor C11 and a capacitor C12;

[0046] The output pin of the digital isolator U1 is connected to the input pin of the gate driver U2, and the output pin of the digital isolator U1 is also connected to the first negative power supply voltage through the resistor R4;

[0047] The output pin of the gate driver U2 is connected to the second electrode of the switching device Q1 and one end of the resistor R8 through the resistor R6; the output pin of the gate driver U2 is connected to the cathode of the TVS tube D3, and the anode of the TVS tube D3 is connected to one end of the resistor R6 and one end of the resistor R8 through the resistor R7. The other end of the resistor R8 is also connected to the first electrode of the switching device Q1, one end of the capacitor C10, one end of the capacitor C11, and one end of the capacitor C12. The other end of the capacitor C10, the other end of the capacitor C11, and the other end of the capacitor C12 are connected to the first negative power supply voltage.

[0048] Specifically, the gate driver U2 drives the switching device Q1 based on a square wave pulse signal, the first negative power supply voltage may be -3.3V, the model of the digital isolator U1 may be SI826IBCD-C-IS, the model of the gate driver U2 may be IXDN609SI, the AN pin of the digital isolator U1 is connected to one end of the resistor R1, the CAT pin of the digital isolator U1 is connected to one end of the resistor R2, the other end of the resistor R1 forms a first signal input end, the other end of the resistor R2 forms a second signal input end, and the AN pin is also connected to the CAT pin through a capacitor C3. The VDD pin of the digital isolator U1 is connected to a 15V voltage, and the GND pin is connected to a -3.3V voltage. The VOUT pin of the digital isolator U1 is the output pin. The VCC1 pin and VCC2 pin of the gate driver U2 are both connected to a 15V voltage. The IN pin of the gate driver U2 is the input pin. The square wave pulse signal is input to the IN pin through the digital isolator U1. The GND1 pin of the gate driver U2 is connected to a -3.3V voltage. The GND2 pin is connected to the VCC2 pin through a capacitor C9. The VCC2 pin is connected to a 15V voltage, and the GND2 pin is connected to a -3.3V voltage. The OUT1 pin of the gate driver U2 is connected to the OUT2 pin to form an output pin.

[0049] Figure 3 The distribution of the components of the transmission delay calibration device in this embodiment on the PCB is shown. Figure 3 In the figure, the first area is provided with a positive terminal and a negative terminal, the second area is arranged with a film capacitor C1, the third area is arranged with a high-speed switching device Q1, the fourth area is arranged with a driving module, the fifth area is arranged with a Rogowski coil installation section, the sixth area is arranged with a load resistor R Load, the seventh area is arranged with multiple probe interfaces, the eighth area is used to install a coaxial shunt resistor, and the ninth area is arranged with a protective resistor.

[0050] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A 100-ampere-level multi-probe transmission delay calibration device, characterized in that: It includes a resistive load switch module, a driving module and a transmission module, wherein the resistive load switch module is adaptively connected to a calibration object through the transmission module; the resistive load switch module includes a switch device Q1, and the switch device Q1 is adaptively connected to the driving module; The driving module is used to drive the switch device Q1 to make the resistive load switch module generate a calibration signal, and the calibration signal is transmitted to the calibration object through the transmission module.

2. The 100-ampere-level multi-probe transmission delay calibration device according to claim 1, characterized in that: The resistive load switch module further includes a film capacitor C1, a load resistor R Load and a coaxial shunt resistor, one end of the film capacitor C1 is connected to the third electrode of the switch device Q1, the second electrode of the switch device Q1 is connected to the driving module, and the first electrode of the switch device Q1 is electrically connected to one end of the load resistor R Load to form a first connection point; The other end of the load resistor R Load is connected to one end of the coaxial shunt resistor, and the other end of the coaxial shunt resistor is connected to the other end of the film capacitor C1 to form a second connection point; both ends of the film capacitor C1 are loaded with a DC power supply voltage.

3. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The load resistor R Load is a non-inductive resistor.

4. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The switch device Q1 includes an N-type MOSFET switch tube.

5. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The transmission module includes a plurality of high-voltage transmission units connected to the first connection point, and a plurality of low-voltage transmission units connected to the second connection point, and the high-voltage transmission units correspond to the low-voltage transmission units in a one-to-one manner.

6. The 100-ampere-level multi-probe transmission delay calibration device according to claim 5, characterized in that: Any high-voltage transmission unit includes a high-voltage wire and a probe interface connected to a first connection point through the high-voltage wire; any low-voltage transmission unit includes a low-voltage wire and a probe interface connected to a second connection point through the low-voltage wire; the probe interface includes multiple types.

7. The 100-ampere-level multi-probe transmission delay calibration device according to claim 6, characterized in that: All high voltage wires are the same length; all low voltage wires are the same length.

8. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The transmission module includes a Rogowski coil installation section for installing the Rogowski coil, and the Rogowski coil installation section is electrically connected between the first electrode and the first connection point of the switching device Q1.

9. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The driving module includes a digital isolator U1, a gate driver U2, a resistor R4, a resistor R6, a resistor R7, a resistor R8, a capacitor C10, a capacitor C11 and a capacitor C12; The output pin of the digital isolator U1 is connected to the input pin of the gate driver U2, and the output pin of the digital isolator U1 is also connected to the first negative power supply voltage through the resistor R4; The output pin of the gate driver U2 is connected to the second electrode of the switch device Q1 and one end of the resistor R8 through the resistor R6; the output pin of the gate driver U2 is also connected to the cathode of the TVS tube D3, and the anode of the TVS tube D3 is connected to one end of the resistor R6 and one end of the resistor R8 through the resistor R7; The other end of the resistor R8 is connected to the first electrode of the switch device Q1, one end of the capacitor C10, one end of the capacitor C11 and one end of the capacitor C12, and the other end of the capacitor C10, the other end of the capacitor C11 and the other end of the capacitor C12 are connected to the first negative power supply voltage.

10. The 100-ampere-level multi-probe transmission delay calibration device according to claim 2, characterized in that: The film capacitor C1 is also connected in parallel with a protection resistor.

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