Use of additional resistances and capacitances by optimization to solve gate voltage oscillation during short circuit turn-off protection for a semiconductor switch

Patent metadata

Field	Value
Publication number	US-10574152-B2
Application number	US-201715682392-A
Country	US
Kind code	B2
Filing date	Aug 21, 2017
Priority date	Aug 21, 2017
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

Bridge circuits provide a reduced amplitude of gate-source voltage oscillation when the switches switch states during short circuit triggered turnoff for protection. Bridge circuits reduce an amplitude of an oscillation voltage between a gate and a source of a transistor that is utilized as a switch in the bridge circuit. This is beneficial because the reduced amplitude reduces the likelihood of damage to the transistor. A bridge circuit includes a first power rail and a second power rail. The bridge circuit further includes a first circuit having a first switch and a second switch connected in parallel between the first power rail and the second power rail. The bridge circuit further includes at least one passive circuit element connected in parallel with a primary energy flow path of the first circuit to damp oscillation voltage of the first circuit.

First claim

What is claimed is:

1. A bridge circuit comprising:
a first power rail;
a second power rail;
a first circuit having a first switch and a second switch connected in parallel between the first power rail and the second power rail;
at least one passive circuit element connected in parallel with a primary energy flow path of the first circuit to damp oscillation voltage of the first circuit;
an output rail;
a second circuit having a third switch and a fourth switch connected in parallel between the first power rail and the second power rail; and
at least a second passive circuit element connected in parallel with a primary energy flow path of the second circuit to damp oscillation voltage of the second circuit.

2. The bridge circuit of claim 1 wherein each of the first switch and the second switch include a transistor.

3. The bridge circuit of claim 2 wherein the at least one passive circuit element includes at least one of:
a first resistor connected between an emitter or a source of the transistor of the first switch and the emitter or the source of the transistor of the second switch;
a second resistor connected between the emitter or the source of the transistor of the first switch and a collector or a drain of the transistor of the second switch;
a third resistor connected between the collector or the drain of the transistor of the first switch and the collector or the drain of the transistor of the second switch;
a first capacitor connected between the emitter or the source of the transistor of the first switch and the collector or the drain of the transistor of the second switch; or
a second capacitor connected between the collector or the drain of the transistor of the first switch and the collector or the drain of the transistor of the second switch.

4. The bridge circuit of claim 3 wherein the at least one passive circuit element includes the first resistor, the second resistor, the third resistor, the first capacitor, and the second capacitor.

5. The bridge circuit of claim 1 wherein the first circuit provides short-circuit turn-off protection.

6. A bridge circuit comprising:
a first power rail;
a second power rail;
a first circuit having a first switch and a second switch connected in parallel between the first power rail and the second power rail; and
at least one resistor or capacitor connected in parallel with a primary energy flow path of the first circuit to damp oscillation voltage of the first circuit, the at least one resistor or capacitor including at least one of:
a first resistor connected between an emitter or a source of the transistor of the first switch and the emitter or the source of the transistor of the second switch,
a second resistor connected between the emitter or the source of the transistor of the first switch and a collector or a drain of the transistor of the second switch,
a third resistor connected between the collector or the drain of the transistor of the first switch and the collector or the drain of the transistor of the second switch,
a first capacitor connected between the emitter or the source of the transistor of the first switch and the collector or the drain of the transistor of the second switch, or
a second capacitor connected between the collector or the drain of the transistor of the first switch and the collector or the drain of the transistor of the second switch.

7. The bridge circuit of claim 6 wherein each of the first switch and the second switch include a transistor.

8. The bridge circuit of claim 6 wherein the at least one resistor or capacitor includes the first resistor, the second resistor, the third resistor, the first capacitor, and the second capacitor.

9. The bridge circuit of claim 6 wherein the first circuit provides short-circuit turn-off protection between the first power rail and the second power rail.

10. The bridge circuit of claim 6 further comprising:
an output power rail;
a second circuit having a third switch and a fourth switch connected in parallel between the first power rail and the second power rail; and
at least a second resistor or capacitor connected in parallel with a primary energy flow path of the second circuit to damp oscillation voltage of the second circuit.

11. The bridge circuit of claim 10 wherein the first circuit is connected between the first power rail and the output power rail, and the second circuit is connected between the second power rail and the output power rail.

12. The bridge circuit of claim 11 wherein the first circuit and the second circuit include identical circuit elements.

13. The bridge circuit of claim 11 wherein at least one of:
a first input is provided on the first power rail and the second power rail, and a first output is provided on the output power rail and the second power rail; or
a second input is provided on the output power rail and the second power rail, and a second output is provided on the first power rail and the second power rail.

14. The bridge circuit of claim 11 wherein each of the first switch, the second switch, the third switch, and the fourth switch include a transistor.

15. The bridge circuit of claim 14 wherein the at least the second resistor or capacitor includes at least one of:
a fourth resistor connected between an emitter or a source of the transistor of the third switch and the emitter or the source of the transistor of the fourth switch;
a fifth resistor connected between the emitter or the source of the transistor of the third switch and a collector or a drain of the transistor of the fourth switch;
a sixth resistor connected between the collector or the drain of the transistor of the third switch and the collector or the drain of the transistor of the fourth switch;
a third capacitor connected between the emitter or the source of the transistor of the third switch and the collector or the drain of the transistor of the fourth switch; or
a fourth capacitor connected between the collector or the drain of the transistor of the third switch and the collector or the drain of the transistor of the fourth switch.

16. A bridge circuit comprising:
a first power rail;
a second power rail;
a first circuit having a first transistor and a second transistor both connected in parallel between the first power rail and the second power rail;
at least one resistor, capacitor, or inductor connected in parallel with a primary energy flow path of the first circuit to damp oscillation voltage of the first circuit;
an output rail;
a second circuit having a third transistor and a fourth transistor connected in parallel between the first power rail and the second power rail; and
at least a second resistor, capacitor, or inductor connected in parallel with a primary energy flow path of the second circuit to damp oscillation voltage of the second circuit.

17. The bridge circuit of claim 16 wherein the at least one resistor, capacitor, or inductor includes at least one of:
a first resistor connected between an emitter or a source of the first transistor and the emitter or the source of the second transistor;
a second resistor connected between the emitter or the source of the first transistor and a collector or a drain of the second transistor;
a third resistor connected between the collector or the drain of the first transistor and the collector or the drain of the second transistor;
a first capacitor connected between the emitter or the source of the first transistor and the collector or the drain of the second transistor; or
a second capacitor connected between the collector o

Assignees

• Toyota Eng & Mfg North America

Inventors

• Wang Chi-Ming
• Dede Ercan M
• Bucsan George C

Classifications

• H02M7/062 Primary

  Avoiding or suppressing excessive transient voltages or currents · CPC title

• H02M1/34

  Snubber circuits · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• H03K17/165

  by feedback from the output circuit to the control circuit · CPC title

• H03K17/0828

  in composite switches · CPC title