稳压电路、驱动电路及开关电源
By using a voltage regulator circuit in the switching power supply to stabilize the bootstrap capacitor voltage, the problem of damage caused by excessive bootstrap capacitor voltage in SiC and GaN power devices is solved, thus improving the stability and lifespan of the devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHINRY E CONTROLS CO LTD
- Filing Date
- 2025-06-25
- Publication Date
- 2026-07-17
AI Technical Summary
In switching power supplies, the bootstrap floating drive circuit causes a large on-state voltage drop of the parasitic diodes in third-generation semiconductor SiC and GaN power devices, resulting in the bootstrap capacitor voltage exceeding the gate rated voltage of the drive chip and power devices, affecting device stability and lifespan.
A voltage regulator circuit is used to stabilize the voltage across the first bootstrap capacitor to prevent the voltage from exceeding the tolerance limits of the power devices and driver chip. This includes the use of components such as Zener diodes, resistors, capacitors, and low-dropout linear regulators to control the capacitor voltage within a safe range.
It reduces voltage stress on power devices, extends device lifespan, avoids damage to driver chips and power devices, and enhances circuit stability.
Smart Images
Figure CN224520912U_ABST
Abstract
Claims
1. A voltage stabilizing circuit, characterized by comprising: The first terminal of the voltage regulator circuit is connected to the output terminal of the chip protection circuit, the second terminal of the voltage regulator circuit is connected to the first terminal of the first bootstrap capacitor and the first power supply terminal of the first driver chip, and the third terminal of the voltage regulator circuit is connected to the second terminal of the first bootstrap capacitor and the first ground terminal of the first driver chip; the voltage regulator circuit is used to stabilize the voltage between the first terminal of the first bootstrap capacitor and the second terminal of the first bootstrap capacitor.
2. The voltage regulator circuit according to claim 1, characterized in that The voltage regulator circuit includes a first Zener diode. The input terminal of the first Zener diode is connected to the output terminal of the chip protection circuit, the first terminal of the first bootstrap capacitor, and the first power supply terminal of the first driver chip. The output terminal of the first Zener diode is connected to the second terminal of the first bootstrap capacitor and the first ground terminal of the first driver chip.
3. The voltage regulator circuit according to claim 2, characterized in that, The voltage regulator circuit further includes a first resistor, and the input terminal of the first Zener diode is connected to the output terminal of the chip protection circuit, the first terminal of the first bootstrap capacitor, and the first power supply terminal of the first driver chip through the first resistor.
4. The voltage regulator circuit of claim 1, wherein The voltage regulator circuit includes a second resistor, a first capacitor, a second Zener diode, and a transistor. The first end of the second resistor is connected to the output terminal of the chip protection circuit, the first end of the first capacitor, and the collector of the transistor. The second end of the second resistor is connected to the input terminal of the second Zener diode and the base of the transistor. The emitter of the transistor is connected to the first end of the first bootstrap capacitor and the first power supply terminal of the first driver chip. The output terminal of the second Zener diode is connected to the second end of the first bootstrap capacitor and the first ground terminal of the first driver chip.
5. The voltage regulator circuit of claim 1, wherein The voltage regulator circuit includes a second capacitor and a low dropout linear regulator (LDO). The first terminal of the second capacitor is connected to the output terminal of the chip protection circuit and the input terminal of the LDO. The output terminal of the LDO is connected to the first terminal of the first bootstrap capacitor and the first power supply terminal of the first driver chip. The ground terminal of the LDO is connected to the second terminal of the second capacitor, the second terminal of the first bootstrap capacitor, and the first ground terminal of the first driver chip.
6. A drive circuit characterized by comprising: Includes the voltage regulator circuit, first driver chip, first bootstrap capacitor, second bootstrap capacitor, chip protection circuit, first driver module, and second driver module as described in any one of claims 1 to 5; The power supply is connected to the input terminal of the chip protection circuit. The output terminal of the chip protection circuit is connected to the first terminal of the voltage regulator circuit. The second terminal of the voltage regulator circuit is connected to the first terminal of the first bootstrap capacitor and the first power supply terminal of the first driver chip. The first output terminal of the first driver chip is connected to the first input terminal of the first driver module. The third terminal of the voltage regulator circuit is connected to the second terminal of the first bootstrap capacitor, the second input terminal of the first driver module, and the first ground terminal of the first driver chip. The first output terminal of the first driver module is connected to the control terminal of the first switching transistor. The second output terminal of the first driver module is connected to the first terminal of the first switching transistor. The second power supply terminal of the first driver chip is connected to the power supply and the first terminal of the second bootstrap capacitor. The second output terminal of the first driver chip is connected to the first input terminal of the second driver module. The second ground terminal of the first driver chip is connected to the second terminal of the second bootstrap capacitor and the second input terminal of the second driver module. The first output terminal of the second driver module is connected to the control terminal of the second switch transistor. The second output terminal of the second driver module is connected to the first terminal of the second switch transistor. The first terminal of the second switch transistor is grounded. The second terminal of the second switch transistor is connected to the first terminal of the first switch transistor.
7. A drive circuit, characterized by It includes the voltage regulator circuit, the first driver chip, the second driver chip, the first bootstrap capacitor, the second bootstrap capacitor, the chip protection circuit, the first driver module, and the second driver module as described in any one of claims 1 to 5. The power supply is connected to the input terminal of the chip protection circuit. The output terminal of the chip protection circuit is connected to the first terminal of the voltage regulator circuit. The second terminal of the voltage regulator circuit is connected to the first terminal of the first bootstrap capacitor and the first power supply terminal of the first driver chip. The first output terminal of the first driver chip is connected to the first input terminal of the first driver module. The third terminal of the voltage regulator circuit is connected to the second terminal of the first bootstrap capacitor, the second input terminal of the first driver module, and the first ground terminal of the first driver chip. The first output terminal of the first driver module is connected to the control terminal of the first switching transistor. The second output terminal of the first driver module is connected to the first terminal of the first switching transistor. The first power supply terminal of the second driver chip is connected to the power supply and the first terminal of the second bootstrap capacitor. The first output terminal of the second driver chip is connected to the first input terminal of the second driver module. The first ground terminal of the second driver chip is connected to the second terminal of the second bootstrap capacitor and the second input terminal of the second driver module. The first output terminal of the second driver module is connected to the control terminal of the second switch transistor. The second output terminal of the second driver module is connected to the first terminal of the second switch transistor. The first terminal of the second switch transistor is grounded. The second terminal of the second switch transistor is connected to the first terminal of the first switch transistor.
8. The drive circuit according to claim 6 or 7, characterized in that The chip protection circuit includes a third resistor and a first diode. The first end of the third resistor is connected to the power supply, the second end of the third resistor is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the first terminal of the voltage regulator circuit.
9. The drive circuit according to claim 6 or 7, characterized in that, The first switch and the second switch form a bridge arm, and the second terminal of the first switch is connected to the power supply voltage of the bridge arm.
10. A switching power supply, characterized by Includes the driving circuit as described in any one of claims 6 to 9.