Driving voltage detection protection circuit applied to gate driver

Abstract

The utility model discloses a driving voltage detection protection circuit applied to a gate driver, which relates to the field of driving protection circuits, and comprises a time delay module, a comparison module and a switch module, the time delay module and the switch module are connected with power supply voltage, the comparison module is connected between the time delay module and the switch module, and the switch module is connected with the comparison module. The switch module is connected with the gate driver; the switch module comprises a switch device Q1, the comparison module comprises a voltage comparator, the second electrode end of the switch device Q1 is connected with the output end of the voltage comparator, and when the power supply voltage is stable, the voltage comparator controls the switch device Q1 to be switched on, so that the power supply voltage is connected to the gate driver through the switch module. The circuit can ensure that the power supply is stable and then supplies power to the gate driver, so that the working stability of the gate driver is improved, and the condition of load short circuit or fault of the gate driver is reduced.

Description

Technical Field

[0001] The utility model relates to the field of drive protection circuits, in particular to a drive voltage detection protection circuit applied to a gate driver. Background Art

[0002] Existing gate drivers primarily consist of a driver chip and an output stage. The driver chip provides the input signal, and the output gate signal controls the on / off switching of the MOSFET or IGBT, thereby achieving circuit switching. However, traditional gate drivers lack a voltage detection circuit and begin outputting gate signals before a stable power supply is available. This can easily cause erroneous or unstable gate signal operation, leading to failure or short circuits in the driven module, potentially damaging the device and causing losses. Utility Model Content

[0003] In response to the above problems and technical requirements, the inventors have proposed a drive voltage detection protection circuit for a gate driver.

[0004] The technical solution of the utility model is as follows:

[0005] A driving voltage detection protection circuit for a gate driver includes a delay module, a comparison module, and a switch module. The delay module, the comparison module, and the switch module are connected to a power supply voltage. The comparison module is connected between the delay module and the switch module. The switch module is connected to the gate driver.

[0006] The switch module includes a switch device Q1, and the comparison module includes a voltage comparator. The second electrode end of the switch device Q1 is connected to the output end of the voltage comparator. When the power supply voltage is stable, the voltage comparator controls the switch device Q1 to turn on, so that the power supply voltage is connected to the gate driver through the switch module.

[0007] A further technical solution is that the delay module includes a capacitor C5, a capacitor C6, a resistor R4 and a diode D2, wherein:

[0008] One end of the capacitor C5 is connected to one end of the resistor R4 and the cathode of the diode D2, the other end of the capacitor C5 is grounded, and the other end of the resistor R4 is connected to the anode of the diode D2 and the inverting input end of the voltage comparator and is grounded through the capacitor C6.

[0009] A further technical solution is that the comparison module further includes a resistor R5 and a resistor R10, one end of the resistor R5 is connected to one end of the resistor R4, the cathode of the diode D2 and one end of the capacitor C5, and the other end of the resistor R5 is connected to the non-inverting input terminal of the voltage comparator;

[0010] One end of the resistor R10 is connected to the other end of the resistor R5 , and the other end of the resistor R10 is connected to one end of the capacitor C6 and is grounded.

[0011] A further technical solution is that the power supply terminal of the voltage comparator is connected to the power supply voltage, and the ground terminal of the voltage comparator is grounded.

[0012] A further technical solution is that the switching device Q1 includes a transistor.

[0013] A further technical solution is that the switch module further includes a resistor R1 and a resistor R2, wherein:

[0014] One end of the resistor R2 is connected to the output end of the voltage comparator, the other end of the resistor R2 is connected to the resistor R1 and the second electrode end of the switching device Q1, the other end of the resistor R1 is connected to the first electrode end of the switching device Q1, and the first electrode end of the switching device Q1 is connected to the power supply voltage.

[0015] A further technical solution is that the switch module further includes a capacitor C1, one end of the capacitor C1 is connected to the first electrode end of the switch device Q1, and the other end of the capacitor C1 is grounded.

[0016] A further technical solution is that the switch module further includes a resistor R6 and a photoelectric coupler PC1. The photoelectric coupler PC1 is of model HCPL3120 and includes a second pin and a third pin.

[0017] One end of the resistor R6 is connected to the third electrode terminal and the second pin of the switch device Q1 , and the other end of the resistor R6 is connected to the third pin.

[0018] A further technical solution is that the switch module further includes a resistor R9, one end of the resistor R9 is connected to one end of the resistor R6 and the third pin, and the other end of the resistor R9 is connected to the PU signal.

[0019] A further technical solution is that the voltage comparator model includes LM2903.

[0020] The beneficial technical effects of the utility model are:

[0021] The utility model provides a driving voltage detection protection circuit for a gate driver. The driving voltage detection protection circuit can ensure that the power supply is stable before supplying power to the gate driver, thereby improving the stability of the gate driver operation and effectively reducing the situation where the gate signal erroneous operation or unstable operation caused by unstable power supply, thereby avoiding short-circuit damage to the functional module driven by the gate driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The utility model provides a circuit schematic diagram of an embodiment of a drive voltage detection protection circuit for a gate driver. DETAILED DESCRIPTION

[0023] The specific implementation of the present utility model will be further described below with reference to the accompanying drawings.

[0024] The utility model provides a driving voltage detection protection circuit for gate drivers, comprising a delay module, a comparison module and a switch module, wherein:

[0025] The delay module, the comparison module and the switch module are connected to the power supply voltage, the comparison module is connected between the delay module and the switch module, and the switch module is connected to the gate driver;

[0026] The switch module includes a switch device Q1, and the comparison module includes a voltage comparator. The second electrode end of the switch device Q1 is connected to the output end of the voltage comparator. When the power supply voltage is stable, the voltage comparator controls the switch device Q1 to turn on, so that the power supply voltage is connected to the gate driver through the switch module.

[0027] Specifically, when the power supply voltage is stable, the voltage comparator output terminal outputs a low level, the switch device Q1 turns on, and the power supply voltage is connected to the gate driver through the switch module. Conversely, the voltage comparator output terminal outputs a high level, the switch device Q1 turns off, and the power supply voltage cannot be connected to the gate driver through the switch module, thereby achieving the effect of powering the gate driver only when the power supply voltage is stable. This drive voltage detection and protection circuit can ensure that the gate driver is powered only after the power supply is stable, thereby improving the stability of the gate driver's operation and effectively avoiding gate signal malfunction or unstable operation caused by unstable power supply, thereby preventing short-circuit damage to the functional modules driven by the gate driver. In this embodiment, the power supply voltage is 5V. The stable power supply voltage specifically means that the power supply voltage is stable at or above 5V after connection. The specific form and connection method of the delay module, comparison module, and switch module can be referred to the following description.

[0028] Furthermore, the delay module includes a capacitor C5, a capacitor C6, a resistor R4 and a diode D2, wherein one end of the capacitor C5 is connected to one end of the resistor R4 and the negative electrode of the diode D2, the other end of the capacitor C5 is grounded, and the other end of the resistor R4 is connected to the positive electrode of the diode D2 and the reverse input end of the voltage comparator and is grounded through the capacitor C6.

[0029] like Figure 1As shown, the power supply terminal of the voltage comparator is connected to the power supply voltage, the ground terminal of the voltage comparator is grounded, one end of the resistor R4 is connected to the power supply voltage, and the capacitor C6 is charged by the resistor R4, so that the power supply voltage is input to the inverting input terminal of the voltage comparator after a delay. When there is no power supply voltage input, the capacitor C6 can be discharged through the diode D2. The voltage comparator model in this embodiment is LM2903. During specific implementation, the model of the voltage comparator can be selected according to actual needs.

[0030] Furthermore, the comparison module also includes a resistor R5 and a resistor R10, wherein one end of the resistor R5 is connected to one end of the resistor R4, the negative electrode of the diode D2 and one end of the capacitor C5, and the other end of the resistor R5 is connected to the non-inverting input end of the voltage comparator; one end of the resistor R10 is connected to the other end of the resistor R5, and the other end of the resistor R10 is connected to one end of the capacitor C6 and grounded.

[0031] Specifically, the power supply voltage is divided by resistors R5 and R10 and then applied to the non-inverting input of the voltage comparator. Before the power supply voltage stabilizes, the voltage at the non-inverting input of the voltage comparator is greater than the voltage at the inverting input, and the voltage comparator continuously outputs a high level. After the power supply voltage stabilizes, the voltage at the non-inverting input of the voltage comparator is less than the voltage at the inverting input, and the voltage comparator outputs a low level.

[0032] Furthermore, the switch module further includes a resistor R1, a resistor R2, a capacitor C1, a resistor R6, a resistor R9 and a photocoupler PC1, wherein:

[0033] One end of resistor R2 is connected to the output of the voltage comparator, and the other end of resistor R2 is connected to resistor R1 and the second electrode of switch Q1. The other end of resistor R1 is connected to the first electrode of switch Q1, which is connected to the power supply voltage. One end of capacitor C1 is connected to the first electrode of switch Q1, and the other end of capacitor C1 is grounded. Photocoupler PC1 is HCPL3120 and includes a second pin and a third pin. One end of resistor R6 is connected to the third electrode of switch Q1 and the second pin, and the other end of resistor R6 is connected to the third pin. One end of resistor R9 is connected to one end of resistor R6 and the third pin, and the other end of resistor R9 is connected to the PU signal.

[0034] Optionally, the switching device Q1 may be a transistor. In this embodiment, the switching device Q1 is a PNP transistor. For a PNP transistor, the first electrode terminal of the switching device Q1 is the emitter terminal, the second electrode terminal is the base terminal, and the third electrode terminal is the collector terminal. Figure 1As shown, the emitter terminal of the switching device Q1 is connected to a 5V power supply voltage and is also connected to one end of a resistor R1 and one end of a capacitor C1. The other end of the capacitor C1 is grounded, serving as an input filter capacitor. The base terminal of the switching device Q1 is connected to the output terminal of the voltage comparator via a resistor R2. The collector terminal of the switching device Q1 is connected to the second pin of the optocoupler PC1. The PU signal is a low-level signal.

[0035] In this embodiment, when the power supply voltage is unstable, the voltage comparator outputs a high level, turning off the switch Q1. The power supply voltage cannot power the gate driver through the switch Q1 and the optocoupler. When the power supply voltage is stable, the voltage comparator outputs a low level, turning on the switch Q1. The power supply voltage then powers the gate driver through the switch Q1 and the optocoupler. This effectively reduces gate signal malfunctions or unstable operation caused by unstable power supply, thereby preventing short-circuit damage to the functional modules driven by the gate driver. The optocoupler is used to electrically isolate the protection circuit from the gate driver. The gate driver and the output terminal of the optocoupler are connected in a manner consistent with the prior art.

[0036] The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment. It is understood that other improvements and variations directly derived or imagined 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 scope of protection of the present invention.

Claims

1. A drive voltage detection protection circuit for a gate driver, characterized in that: It includes a delay module, a comparison module and a switch module, wherein the delay module, the comparison module and the switch module are connected to the power supply voltage, the comparison module is connected between the delay module and the switch module, and the switch module is connected to the gate driver; The switch module includes a switch device Q1, and the comparison module includes a voltage comparator. The second electrode end of the switch device Q1 is connected to the output end of the voltage comparator. When the power supply voltage is stable, the voltage comparator controls the switch device Q1 to turn on, so that the power supply voltage is connected to the gate driver through the switch module.

2. The driving voltage detection protection circuit for a gate driver according to claim 1, characterized in that: The delay module includes capacitor C5, capacitor C6, resistor R4 and diode D2, wherein: One end of the capacitor C5 is connected to one end of the resistor R4 and the cathode of the diode D2, the other end of the capacitor C5 is grounded, and the other end of the resistor R4 is connected to the anode of the diode D2 and the inverting input end of the voltage comparator and is grounded through the capacitor C6.

3. The driving voltage detection protection circuit for a gate driver according to claim 2, characterized in that: The comparison module further includes a resistor R5 and a resistor R10, wherein: One end of the resistor R5 is connected to one end of the resistor R4, the cathode of the diode D2 and one end of the capacitor C5, and the other end of the resistor R5 is connected to the non-inverting input end of the voltage comparator; One end of the resistor R10 is connected to the other end of the resistor R5 , and the other end of the resistor R10 is connected to one end of the capacitor C6 and is grounded.

4. The driving voltage detection protection circuit for a gate driver according to claim 1, wherein: The power supply terminal of the voltage comparator is connected to the power supply voltage, and the ground terminal of the voltage comparator is grounded.

5. The driving voltage detection protection circuit for a gate driver according to claim 1, characterized in that: The switching device Q1 includes a transistor.

6. The driving voltage detection protection circuit for a gate driver according to claim 1, characterized in that: The switch module further includes a resistor R1 and a resistor R2, wherein: One end of the resistor R2 is connected to the output end of the voltage comparator, the other end of the resistor R2 is connected to the resistor R1 and the second electrode end of the switching device Q1, the other end of the resistor R1 is connected to the first electrode end of the switching device Q1, and the first electrode end of the switching device Q1 is connected to the power supply voltage.

7. The driving voltage detection protection circuit for a gate driver according to claim 6, characterized in that: The switch module further includes a capacitor C1 , one end of the capacitor C1 is connected to the first electrode end of the switch device Q1 , and the other end of the capacitor C1 is grounded.

8. The driving voltage detection protection circuit for a gate driver according to claim 6, characterized in that: The switch module further includes a resistor R6 and a photoelectric coupler PC1. The photoelectric coupler PC1 is HCPL3120 and includes a second pin and a third pin. One end of the resistor R6 is connected to the third electrode terminal and the second pin of the switch device Q1 , and the other end of the resistor R6 is connected to the third pin.

9. The driving voltage detection protection circuit for a gate driver according to claim 8, characterized in that: The switch module further includes a resistor R9 , one end of the resistor R9 is connected to one end of the resistor R6 and the third pin, and the other end of the resistor R9 is connected to the PU signal.

10. The driving voltage detection protection circuit for a gate driver according to claim 1, characterized in that: The voltage comparator model includes LM2903.

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