Circuit for shortening first-class short circuit protection time of silicon carbide module

Abstract

The utility model discloses a circuit for shortening one-class short circuit protection time of a silicon carbide module, which comprises a grid isolation driving chip U6, a diode D51, a capacitor C147 and a resistor R67, a power supply pin VCC2 of the grid isolation driving chip U6 is connected with a power supply end VP15VUH, an anode of the diode D51 is grounded, the capacitor C147 is connected between a cathode and an anode of the diode D51, and the resistor R67 is connected with the power supply pin VCC2 of the grid isolation driving chip U6. The cathode of the diode D51 is connected to a desaturation detection pin DESAT of the gate isolation driving chip U6, and the resistor R67 is connected between the cathode of the diode D51 and the power supply end VP15VUH. When the circuit works, the capacitor C147 is charged through the resistor R67, the first-class short circuit protection response time can be made to be smaller than 1.3 uS by selecting the resistance value of the resistor R67, and then the function of shortening the first-class short circuit protection time of the silicon carbide module is achieved.

Description

Technical Field

[0001] This utility model relates to short-circuit protection circuits, and more particularly to a circuit for shortening the short-circuit protection time of a silicon carbide module. Background Technology

[0002] Currently, among the various gate isolation driver chips on the market, the charging current of the built-in desaturation detection constant current source is less than 500uA, and the external desaturation detection pin requires a capacitor greater than 33pF. Combined with the internal response time, this results in an actual desaturation detection time greater than 2uS. This time is greater than the short-circuit time of 1.3uS that current silicon carbide chips can withstand, and cannot meet the circuit's requirements for short-circuit protection time. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a circuit that can shorten the short-circuit protection time in the case of silicon carbide module driving, in view of the shortcomings of the prior art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0005] A circuit for shortening the short-circuit protection time of a silicon carbide module includes a gate isolation driver chip U6, a diode D51, a capacitor C147, and a resistor R67. The power supply pin VCC2 of the gate isolation driver chip U6 is connected to the power supply terminal VP15V_UH. The anode of the diode D51 is grounded. The capacitor C147 is connected between the cathode and anode of the diode D51. The cathode of the diode D51 is connected to the desaturation detection pin DESAT of the gate isolation driver chip U6. The resistor R67 is connected between the cathode of the diode D51 and the power supply terminal VP15V_UH.

[0006] Preferably, the desaturation detection pin DESAT is also connected to the sampling branch VDS.

[0007] Preferably, the resistance of the resistor R67 is 15KΩ.

[0008] Preferably, it includes a capacitor C129, which is connected between the power supply terminal VP15V_UH and ground.

[0009] Preferably, the gate isolation driver chip U6 is a chip with the model number UCC21750.

[0010] In the circuit disclosed in this utility model for shortening the Class I short-circuit protection time of a silicon carbide module, the diode D51 is connected in reverse between the desaturation detection pin DESAT of the gate isolation driver chip U6 and ground. The resistor R67 and the capacitor C147 are connected in series between the power supply terminal VP15V_UH and ground, and their connection point is connected to the desaturation detection pin DESAT of the gate isolation driver chip U6. When the circuit is working, the capacitor C147 is charged through the resistor R67. By selecting the resistance value of the resistor R67, the Class I short-circuit protection response time can be made less than 1.3uS, thereby realizing the function of shortening the Class I short-circuit protection time of the silicon carbide module. Attached Figure Description

[0011] Figure 1 This is the circuit schematic diagram of this utility model;

[0012] Figure 2 This is the internal schematic diagram of a gate-isolated driver chip. Detailed Implementation

[0013] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0014] This utility model discloses a circuit for shortening the short-circuit protection time of a silicon carbide module, combined with... Figure 1 and Figure 2 As shown, it includes a gate isolation driver chip U6, a diode D51, a capacitor C147, and a resistor R67. The power supply pin VCC2 of the gate isolation driver chip U6 is connected to the power supply terminal VP15V_UH. The anode of the diode D51 is grounded. The capacitor C147 is connected between the cathode and anode of the diode D51. The cathode of the diode D51 is connected to the desaturation detection pin DESAT of the gate isolation driver chip U6. The resistor R67 is connected between the cathode of the diode D51 and the power supply terminal VP15V_UH.

[0015] In the above circuit, diode D51 is connected in reverse between the desaturation detection pin DESAT of the gate isolation driver chip U6 and ground. Resistor R67 and capacitor C147 are connected in series between the power supply terminal VP15V_UH and ground. The connection point of the two is connected to the desaturation detection pin DESAT of the gate isolation driver chip U6. When the circuit is working, capacitor C147 is charged through resistor R67. By selecting the resistance value of resistor R67, the response time of Class I short circuit protection can be less than 1.3uS, thereby realizing the function of shortening the Class I short circuit protection time of silicon carbide module.

[0016] Please see Figure 1In this embodiment, the desaturation detection pin DESAT is also connected to the sampling branch VDS.

[0017] As a preferred embodiment, the gate isolation driver chip U6 is a UCC21750 chip. For details regarding the internal circuit structure of the gate isolation driver chip U6, please refer to [link to relevant documentation]. Figure 2 Using a constant current source to control capacitor C BLK During charging, an external resistor R67 is added to pull the voltage up to 15V or 18V, and capacitor C147 is charged through resistor R67. Adjusting or selecting the resistance value of resistor R67 can achieve a short-circuit protection response time of less than 1.3µs. In this embodiment, the preferred resistance value of resistor R67 is as follows: the resistance value of resistor R67 is 15KΩ.

[0018] Furthermore, this embodiment also includes a capacitor C129, which is connected between the power supply terminal VP15V_UH and ground. The capacitor C129 mainly serves a filtering function.

[0019] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. All modifications, equivalent substitutions or improvements made within the technical scope of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A circuit for shortening the short-circuit protection time of a silicon carbide module, characterized in that, The device includes a gate isolation driver chip U6, a diode D51, a capacitor C147, and a resistor R67. The power supply pin VCC2 of the gate isolation chip U6 is connected to the power supply terminal VP15V_UH. The anode of the diode D51 is grounded. The capacitor C147 is connected between the cathode and anode of the diode D51. The cathode of the diode D51 is connected to the desaturation detection pin DESAT of the gate isolation driver chip U6. The resistor R67 is connected between the cathode of the diode D51 and the power supply terminal VP15V_UH.

2. The circuit for shortening the short-circuit protection time of a silicon carbide module as described in claim 1, characterized in that, The desaturation detection pin DESAT is also connected to the sampling branch VDS.

3. The circuit for shortening the short-circuit protection time of a silicon carbide module as described in claim 1, characterized in that, The resistance of resistor R67 is 15KΩ.

4. The circuit for shortening the short-circuit protection time of a silicon carbide module as described in claim 1, characterized in that, It includes a capacitor C129, which is connected between the power supply terminal VP15V_UH and ground.

5. The circuit for shortening the short-circuit protection time of a silicon carbide module as described in claim 1, characterized in that, The gate isolation driver chip U6 is a chip with the model number UCC21750.

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