Driver circuit for switching device
A driver circuit that lowers the dependence of the loss in the wide gap semiconductor device upon the temperature is provided. A gate driver circuit for voltage driven power semiconductor switching device includes a power semiconductor switching device, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a unit for detecting a temperature of the switching device. The temperature of the power semiconductor switching device is detected, and a gate drive voltage or a gate drive resistance value is changed based on the detected temperature.
1. A gate driver circuit for a wide gap type power semiconductor switching device, comprising, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a diode between the emitter control terminal or the source control terminal of the power semiconductor switching device and the gate terminal of the power semiconductor switching device,
wherein:
a temperature of the power semiconductor switching device is detected based on a forward voltage drop of the diode,
in response to an increase in the detected temperature, the drive circuit raises a gate drive voltage or reduces a gate drive resistance value to adjust the drive signal to continue driving the switching device with an increased drive signal to decrease dependence of loss in the wide gap type semiconductor switching device upon the increase in the detected temperature,
wherein the wide gap type power semiconductor switching device is comprised of a SiC or a GaN wide gap type power semiconductor switching device,
wherein a detection operation of the forward voltage drop of the diode is conducted during an off-period of the power semiconductor switching device, and
wherein the off period of the power semiconductor switching device is a period based on an off signal of a PWM signal which alternates between an on signal and the off signal.
2. The gate driver circuit according to claim 1 , wherein the circuit further comprises a constant current circuit coupled to the collector/emitter path or the source/drain path of the power semiconductor switching device and to the diode, wherein the constant current circuit is configured to be brought into and ON state when the PWM signal is an OFF signal and to be brought into an OFF state when the PWM signal is an ON signal.
3. A gate driver circuit for a wide gap type power semiconductor switching device, comprising, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a diode between the emitter control terminal or the source control terminal of the power semiconductor switching device and the gate terminal of the power semiconductor switching device,
wherein:
a temperature of the power semiconductor switching device is detected based on a forward voltage drop of the diode,
in response to an increase in the detected temperature, the drive circuit raises a gate drive voltage or reduces a gate drive resistance value to adjust the drive signal to continue driving the switching device with an increased drive signal to decrease dependence of loss in the wide gap type semiconductor switching device upon the increase in the detected temperature,
wherein the wide gap type power semiconductor switching device is comprised of a SIC or a GaN wide gap type power semiconductor switching device,
wherein a detection operation of the forward voltage drop of the diode is conducted during an off-period of the power semiconductor switching device, and
wherein the off period of the power semiconductor switching device is a period based on an off signal of a PWM signal which alternates between an on signal and the off signal,
wherein the diode is incorporated in the power semiconductor switching device, and
wherein the power semiconductor switching device is comprised of a junction type FET (Field Effect Transistor) and the diode is comprised of a parasitic diode formed between a gate and a source of the junction type FET.
4. The gate driver circuit according to claim 3 , wherein the circuit further comprises a constant current circuit coupled to the collector/emitter path or the source/drain path of the power semiconductor switching device and to the diode, wherein the constant current circuit is configured to be brought into and ON state when the PWM signal is an OFF signal and to be brought into an OFF state when the PWM signal is an ON signal.