High-voltage diode reverse leakage current detection device

Abstract

The invention relates to a high-voltage diode reverse leakage current detection device which is characterized in that one end of a third resistor R3 is connected with a P pole of a high-voltage diode D2, the other end of the third resistor R3 is connected with GND, and an N pole of the high-voltage diode D2 is connected with a high-voltage power supply X1; the voltage detection end of the third resistor R3 is connected with the positive end of the amplifier N1, one end of the second resistor R2 is connected with the negative end of the amplifier, the other end of the second resistor R2 is grounded, one end of the first resistor R1 is connected with the negative end of the amplifier, and the other end of the first resistor R1 is connected with the output end of the amplifier. And a direct current voltage gear of a digital multimeter is detected at a test end. The beneficial effects of the invention are that the high input impedance amplifier is designed to solve the high input impedance problem of the test of the test instrument, the voltage of hundreds of uV at the input end is amplified to the voltage of dozens of mV, and the voltage is detected by the DC voltage shift of the digital multimeter, so that the high input impedance amplifier has the characteristics of low cost, convenient use, high safety, low cost, accurate test parameters and the like; the method has high use value in actual test application.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, specifically a high-voltage diode reverse leakage current detection device. Background Technology

[0002] Detecting reverse leakage current in high-voltage diodes is significantly more challenging than testing leakage current in conventional diodes. This is because high-voltage diodes operate at several kilovolts of DC voltage, raising safety concerns, while the reverse leakage current is relatively small, only in the nA range. Therefore, testing instruments with high input impedance are required. Existing methods for detecting reverse leakage current in high-voltage diodes utilize dedicated leakage current testing equipment, such as the IR reverse leakage current testing device for high-voltage diodes disclosed in patent application number 201610691890.4. These devices are complex in structure, expensive, and inconvenient to move around in. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing leakage current testing equipment, such as high cost and inconvenience in mobile use, and to provide a high-voltage diode reverse leakage current detection device. This invention can be widely applied in the fields of signal processing technology and testing technology.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A high-voltage diode reverse leakage current detection device, characterized in that it comprises:

[0006] The voltage detection terminal of the third resistor R3 is connected to the P terminal of the high-voltage diode D2, the other end of the third resistor R3 is connected to GND, and the N terminal of the high-voltage diode D2 is connected to the high-voltage power supply X1.

[0007] The voltage detection terminal of the third resistor R1 is connected to the positive input terminal of the high input impedance amplifier N1. The negative input terminal of amplifier N1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is grounded. The negative input terminal of amplifier N1 is then connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the output terminal of amplifier N1. The output terminal of amplifier N1 is connected to the test terminal X2. The amplifier amplifies the voltage by 101 times in the positive direction, increasing the voltage of several hundred uV at the input terminal to tens of mV. The voltage is then detected at the test terminal using a digital multimeter in DC voltage mode.

[0008] Based on the above technical solutions, the following further technical solutions are proposed:

[0009] The P-terminal of the high-voltage diode D2 is connected to the positive terminal of the Zener diode and the positive input terminal of the amplifier N1, while the negative terminal of the Zener diode is grounded.

[0010] In the technical solution of this invention,

[0011] The third resistor R3 is connected in series between the P terminal of the high-voltage diode D2 and GND. The third resistor R3 converts a current of several nA into a voltage of several hundred uV. The amplifier is configured to a forward amplification of 101 times, amplifying the input voltage of several hundred uV to a voltage of tens of mV. This voltage can be detected using a digital multimeter in DC voltage mode. The reverse leakage current parameter of the diode can be calculated from the detected voltage value.

[0012] The third resistor R3 is connected in parallel with a Zener diode to design a high-voltage protection circuit, ensuring that the voltage value at the detection end does not exceed the Zener diode voltage of 12V, thus achieving high-voltage safety protection from the high-voltage end to the low-voltage detection end.

[0013] The beneficial effects of this invention are that it uses current to voltage parameters to design a high-voltage protection circuit for protection from high voltage to low voltage, and designs a high input impedance amplifier to solve the high input impedance problem of the test instrument. It amplifies the voltage of several hundred uV at the input terminal to tens of mV, which can be detected by a digital multimeter in DC voltage mode. It has the characteristics of low cost, convenient use, high safety, low cost and accurate test parameters, and has high application value in practical test applications. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below:

[0015] Figure 1 This is the overall schematic diagram of the detection circuit;

[0016] Figure 2 This is a circuit diagram for converting the reverse leakage current of a high-voltage diode to a voltage.

[0017] Figure 3 This is a circuit diagram for a forward amplifier of the sampled voltage signal. Detailed Implementation

[0018] like Figure 1As shown, this invention provides a high-voltage diode reverse leakage current detection device, including a sampling third resistor R3 connected in series between the high-voltage diode D2 and GND. When the high-voltage DC voltage of the high-voltage power supply X1 is applied to the N terminal of the diode D2, the reverse leakage current generated by the diode is converted into a weak DC voltage signal through the third resistor R3. The weak DC voltage signal at the voltage detection terminal of the third resistor R3 is connected to the D3 Zener diode (12V) to prevent the voltage at the detection terminal from being too high and causing safety damage to the tester if the high-voltage diode breaks down. The weak DC voltage signal at the voltage detection terminal of the third resistor R3 is amplified 101 times by a high input impedance non-inverting amplifier composed of amplifier N1, so that the weak DC voltage signal is amplified to a voltage signal of tens of mV at the TEST terminal. The DC voltage test data can be recorded by a digital multimeter or a data acquisition card. The reverse leakage current value (nA level) of the high-voltage diode can be calculated by reverse calculation based on the measured DC voltage value.

[0019] Figure 2 It is a high-voltage diode reverse leakage current to voltage conversion circuit. Figure 2 In this circuit, a 400V to 3000V DC high voltage (output current limited to 1mA) is connected to the inverting N-terminus of the high-voltage diode D2 under test. One path of the forward P-terminus of diode D2 is connected to one end of the third conversion resistor R3, and the other path is connected to the N-terminus of the Zener diode D3. The other ends of both the first conversion resistor R3 and the Zener diode D3 are connected to GND. The high-voltage diode reverse leakage current to voltage conversion circuit converts the reverse leakage current parameter of the high-voltage diode into a weak DC voltage signal.

[0020] Figure 3 This is a circuit diagram for a forward amplifier of the sampled voltage signal. Figure 3 In this circuit, the weak DC voltage signal Vin is connected to the positive input terminal of the high input impedance amplifier N1. The negative input terminal of N1 is connected to the first feedback resistor R1, and the second resistor R2 is connected to GND. The other end of the first resistor R1 is connected to the output terminal TEST of the amplifier. The amplification factor of the non-inverting amplifier is (1 + R2 / R1), which is 101 times. The function of the sampling voltage signal forward amplification circuit is to amplify the weak DC voltage signal Vin into a measurable mV-level DC voltage for easy testing and acquisition by a digital multimeter or data acquisition card. The measured voltage value can be used to calculate the reverse leakage current value (nA level) of the high-voltage diode.

Claims

1. A high-voltage diode reverse leakage current detection device, characterized in that... include: The voltage detection terminal of the third resistor R3 is connected to the P terminal of the high-voltage diode D2, the other end of the third resistor R3 is connected to GND, and the N terminal of the high-voltage diode D2 is connected to the high-voltage power supply X1. The voltage detection terminal of the third resistor R3 is connected to the positive input terminal of the high input impedance amplifier N1. The negative input terminal of amplifier N1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is grounded. The negative input terminal of amplifier N1 is then connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the output terminal of amplifier N1. The output terminal of amplifier N1 is connected to the test terminal X2, which amplifies the voltage at the input terminal from hundreds of uV to tens of mV, and detects it at the test terminal using the DC voltage setting of a digital multimeter.

2. The high-voltage diode reverse leakage current detection device according to claim 1, characterized in that: The P-terminal of the high-voltage diode D2 is connected to the positive terminal of the Zener diode and the positive input terminal of the amplifier N1, while the negative terminal of the Zener diode is grounded.

Images