Method and apparatus for driving a power device

Patent metadata

Field	Value
Publication number	US-9531378-B1
Application number	US-201514845081-A
Country	US
Kind code	B1
Filing date	Sep 3, 2015
Priority date	Sep 3, 2015
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

Aspects of the disclosure provide a circuit for driving a power switch. The circuit includes a first circuit configured to provide a charging current to charge a control terminal of the power switch, a second circuit configured to provide a discharging current to discharge the control terminal of the power switch, and a control circuit configured to provide control signals to the first circuit and the second circuit to activate/deactivate the first circuit and the second circuit. At least one of the charging current and the discharging current ramps from a first level to a second level at a rate.

First claim

What is claimed is:

1. A circuit, comprising:
a first circuit configured to provide a charging current to charge a control terminal of a power switch;
a second circuit configured to provide a discharging current to discharge the control terminal of the power switch;
an inductive component coupled to the control terminal of the power switch and directly grounded; and
a control circuit configured to provide control signals to the first circuit and the second circuit to activate/deactivate the first circuit and the second circuit, at least one of the charging current and the discharging current ramping from a first level to a second level at a rate.

2. The circuit of claim 1 , wherein the first circuit is configured to provide a pull-up current to pull up a voltage at a gate terminal of a metal-oxide-semiconductor field effect transistor (MOSFET) in the power switch to turn on the MOSFET.

3. The circuit of claim 2 , wherein the power switch is implemented using a silicon carbide MOSFET.

4. The circuit of claim 1 , wherein the first circuit is configured to provide a pull-up current ramping up from the first level to the second level at the rate as a function of an inductance of the inductive component.

5. The circuit of claim 4 , wherein the first circuit includes a current mirror configured to mirror a current flowing through the inductive component to generate the pull-up current.

6. The circuit of claim 5 , wherein the first circuit includes a switch configured to couple the inductive component to the current mirror in response to one of the control signals from the control circuit.

7. The circuit of claim 6 , wherein the first circuit includes a diode configured to conduct a freewheel current of the inductive component when the inductive component is de-coupled from the current mirror.

8. A method for driving a power switch, comprising:
activating a first circuit configured to provide a charging current to charge a control terminal of the power switch;
generating, by the first circuit, a current ramping from a first level to a second level at a rate as a function of an inductive component coupled to the control terminal of the power switch and directly grounded; and
providing the current to a control terminal of the power switch to turn on/off the power switch.

9. The method of claim 8 , wherein providing the current to the control terminal of the power switch to turn on/off the power switch further comprises:
providing the current to a gate terminal of a metal-oxide-semiconductor field effect transistor (MOSFET) in the power switch to turn on the MOSFET.

10. The method of claim 9 , wherein:
providing the current to the gate terminal of a silicon carbide MOSFET to turn on the silicon carbide MOSFET.

11. The method of claim 8 , wherein generating, by the first circuit, the current ramping from the first level to the second level at the rate further comprises:
generating a pull-up current ramping up from the first level to the second level at the rate as a function of an inductance of the inductive component.

12. The method of claim 11 , wherein generating the pull-up current ramping up from the first level to the second level at the rate as the function of the inductance of the inductive component further comprises:
mirroring a current flowing through the inductive component to generate the pull-up current.

13. The method of claim 12 , wherein mirroring the current flowing through the inductive component to generate the pull-up current further comprises:
coupling the inductive component to a current mirror to flow the current in the inductive component;
decoupling the inductive component from the current mirror; and
flowing a freewheel current of the inductive component via a diode.

14. An apparatus, comprising:
a power switch configured to be turned on/off by a driver circuit; and
the driver circuit comprising:
a first circuit configured to provide a charging current to charge a control terminal of the power switch;
a second circuit configured to provide a discharging current to discharge the control terminal of the power switch;
an inductive component coupled to the control terminal of the power switch and directly grounded; and
a control circuit configured to provide control signals to the first circuit and the second circuit to activate/deactivate the first circuit and the second circuit, at least one of the charging current and the discharging current ramping from a first level to a second level at a rate.

15. The apparatus of claim 14 , wherein the power switch includes a metal-oxide-semiconductor field effect transistor (MOSFET), and the first circuit is configured to provide a pull-up current to pull up a voltage at a gate terminal of the MOSFET to turn on the MOSFET.

16. The apparatus of claim 15 , wherein the power switch is implemented using a silicon carbide MOSFET.

17. The apparatus of claim 14 , wherein the first circuit comprises the inductive component having an inductance, and the rate is a function of the inductance.

18. The apparatus of claim 17 , wherein the first circuit includes a current mirror configured to mirror a current flowing through the inductive component to generate a pull-up current.

19. The apparatus of claim 18 , wherein the first circuit includes a switch configured to couple the inductive component to the current mirror in response to one of the control signals from the control circuit.

20. The apparatus of claim 19 , wherein the first circuit includes a diode configured to conduct a freewheel current of the inductive component when the inductive component is de-coupled from the current mirror.

Assignees

• Toyota Motor Eng & Mfg North America Inc
• Virginia Tech Intellectual Properties Inc

Inventors

• Shin Jongwon
• Wang Chi-Ming
• Ngo Khai

Classifications

• H03K17/163

  Soft switching · CPC title

• H03K17/687 Primary

  the devices being field-effect transistors · CPC title

• G05F3/24 Primary

  wherein the transistors are of the field-effect type only (G05F3/205, G05F3/26, G05F3/30 take precedence) · CPC title