Current-source gate driver

• US 20100019807A1
• Filed: 02/23/2009
• Published: 01/28/2010
• Est. Priority Date: 02/22/2008
• Status: Active Grant

• Current Assignee: GaN Power semiconductor (Foshan) Co., Ltd.
• Original Assignee: Queen's University At Kingston
• Inventors: Zhang, Zhiliang, Liu, Yan-Fei
• Granted Patent: US 8,085,083 B2
• Time in Patent Office: Days
• US Class Current: 327/109
• CPC Class Codes: H03K 17/145 in field-effect transistor switches
• CPC Class Codes: H03K 2217/0036 Means reducing energy consumption

Abstract

Provided is a current-source gate driver for use with a switching device having a gate capacitance, including an input terminal for receiving a DC voltage; a first switch connected between the input terminal and an output terminal; a second switch connected between the output terminal and a circuit common; a series circuit comprising a first capacitor and an inductor, the series circuit connected between the input terminal and the output terminal; wherein the gate capacitance of the switching device is connected between the output terminal and the circuit common. The current-source gate driver improves efficiency of the power switching devices of a voltage regulator module or other switching converter.

Claims

1. A current-source gate drive circuit for use with a switching device having a gate capacitance, comprising:

an input terminal for receiving a DC voltage;

a first switch connected between the input terminal and an output terminal;

a second switch connected between the output terminal and a circuit common;

a series circuit comprising a first capacitor and an inductor, the series circuit connected between the input terminal and the output terminal;

wherein the gate capacitance of the switching device is connected between the output terminal and the circuit common.

2. The current-source gate drive circuit of claim 1, further comprising a second capacitor connected between a node between the first capacitor and the inductor, and the circuit common.

3. The current-source gate drive circuit of claim 2, further comprising a third capacitor connected between the node and the inductor.

4. The current-source gate drive circuit of claim 1, wherein the circuit common is ground.

5. The current-source gate drive circuit of claim 1, wherein the switching device is a synchronous power switching device of a buck converter.

6. The current-source gate drive circuit of claim 1, wherein the switching device is a low side power switching device of a bridge leg.

7. The current-source gate drive circuit of claim 1, wherein the switching device is a power switching device selected from a MOSFET (metal oxide semiconductor field effect transistor), an IGBT (insulated gate bipolar transistor), and a MCT (MOS controlled thyristor).

18. A voltage regulator having a high side power switching device and a low side power switching device, each said power switching device having a gate capacitance, comprising:

the current-source gate drive circuit of claim 1 for driving the high side power switching device; and

the current-source gate drive circuit of claim 7 for driving the low side power switching device.

19. The voltage regulator of claim 18, wherein the inductor of the current-source gate drive circuit for driving the high side power switching device shares a magnetic component with the inductor of the current-source gate drive circuit for driving the low side power switching device.

8. A current-source gate drive circuit for use with a switching device having a gate capacitance, comprising:

an input terminal for receiving a DC voltage;

a rectifier connected between the input terminal and a first node;

a first switch connected between the first node and an output terminal;

a second switch connected between the output terminal and a floating point;

a series circuit comprising a first capacitor and an inductor, the series circuit connected between the first node and the output terminal; and

a second capacitor connected between the first node the floating point;

wherein the gate capacitance of the switching device is connected between the output terminal and the floating point.

9. The current-source gate drive circuit of claim 8, wherein the series circuit is connected between the floating point and the output terminal.

10. The current-source gate drive circuit of claim 8, wherein the switching device is a control power switching device of a buck converter.

11. The current-source gate drive circuit of claim 8, wherein the switching device is a high side power switching device of a bridge leg.

12. The current-source gate drive circuit of claim 8, wherein the switching device is a power switching device selected from a MOSFET (metal oxide semiconductor field effect transistor), an IGBT (insulated gate bipolar transistor), and a MCT (MOS controlled thyristor).

13. A current-source gate drive circuit for use with a switching device having a gate capacitance, comprising:

an input terminal for receiving a DC voltage;

a rectifier connected between the input terminal and a first node;

a first switch connected between the first node and an output terminal;

a second switch connected between the output terminal and a floating point;

a series circuit comprising a first capacitor and second capacitor, the series circuit connected between the first node and the floating point; and

an inductor connected between a point between the first and second capacitors and the output terminal;

wherein the gate capacitance of the switching device is connected between the output terminal and the floating point.

14. The current-source gate drive circuit of claim 13, further comprising a third capacitor connected in series with the inductor, between the first and second capacitors and the output terminal.

15. The current-source gate drive circuit of claim 13, wherein the switching device is a control power switching device of a buck converter.

16. The current-source gate drive circuit of claim 13, wherein the switching device is a high side power switching device of a bridge leg.

17. The current-source gate drive circuit of claim 13, wherein the switching device is a power switching device selected from a MOSFET (metal oxide semiconductor field effect transistor), an IGBT (insulated gate bipolar transistor), and a MCT (MOS controlled thyristor).

20. A method of controlling switching of a switching device having a gate capacitance, comprising:

(a) providing a constant current source in a first direction to charge the gate capacitance of the switching device;

(b) clamping the voltage across the gate capacitance to a high value, to turn the switching device on;

(c) reversing direction of the constant current source to discharge the gate capacitance of the switching device; and

(d) clamping the voltage across the gate capacitance to a low value, to turn the switching device off;

wherein the constant current source comprises an inductor current.

21. The method of claim 20, wherein the switching device is the high side power switching device or the low side power switching device of a voltage regulator or a bridge leg.

22. A method of controlling independently the switching of high side and low side power switching devices of a voltage regulator, each said power switching device having a gate capacitance, comprising:

independently applying the method of claim 20 to each of the high side and low side power switching devices of the voltage regulator.

23. The method of claim 22, wherein inductor currents applied to the high side and low side power switching devices are not equal.

24. The method of claim 22, further comprising:

applying the method of claim 20 to the high side power switching device of the voltage regulator using a high inductor current; and

applying the method of claim 20 to the low side power switching device of the voltage regulator using a low inductor current.

25. The method of claim 22, wherein the voltage regulator is a buck converter.

26. The method of claim 20, wherein controlling includes repeating steps (a) to (d) once per cycle at a frequency of at least 300 kHz.

27. The method of claim 26, wherein the frequency is at least 1 MHz.