BUCK CONVERTER SYSTEM WITH AN ASYMMETRIC THRESHOLD VOLTAGE GATE DRIVE CIRCUIT DESIGN

Abstract

A buck converter with an asymmetric threshold voltage of its gate drive circuit design for improving power efficiency while keeping the gate drive design simple.

Description

Claims

1. A DC-to-DC buck converter comprising: a gate drive circuit comprising: a high-side transistor having a high threshold voltage; anda low-side transistor having a low threshold voltage, wherein the low threshold voltage is approximately 20 to 50 percent lower than the high threshold voltage.

2. The DC-to-DC buck converter of claim 1, wherein the gate drive circuit is adapted to drive a gate capacitance of a switching device of the DC-to-DC buck converter.

3. The DC-to-DC buck converter of claim 1, wherein the high-side and low-side transistors each have one or more intrinsic body diodes, respectively, and wherein the low threshold voltage is closer to a forward voltage of the one or more intrinsic body diodes that the high threshold voltage, respectively.

4. The DC-to-DC buck converter of claim 3, wherein the low threshold voltage is adapted so that a channel of the low-side transistor conducts a current instead of the one or more intrinsic body diode during deadtime.

5. The DC-to-DC buck converter of claim 1, wherein said difference between in said threshold voltages consists of a thinner gate oxide of the low-side transistor relative to the high-side transistor.

6. The DC-to-DC buck converter of claim 1, wherein each transistor is coupled to a turn-on switch operatively associated with a turn-off switch, respectively, and wherein the turn-off switch of the high-side transistor is configured to prevent parasitic turn on at negative currents and prevent the high-side transistor from entering avalanche during continuous mode.

7. The DC-to-DC buck converter of claim 6, wherein the turn-off switch of the high-side transistor is configured with an active control to enable prevention of said parasitic turn on and said entrance of avalanche.

8. A method of controlling switching of a switching device of a DC-to-DC buck converter, comprising: providing a gate drive circuit comprising: a high-side transistor having a high threshold voltage; anda low-side transistor having a low threshold voltage, wherein the low threshold voltage is approximately 20 to 50 percent lower than the high threshold voltage.

9. The method of claim 8, wherein said difference between in said threshold voltages consists of a thinner gate oxide of the low-side transistor relative to the high-side transistor.

10. The method of claim 8, wherein each transistor is coupled to a turn-on switch operatively associated with a turn-off switch, respectively, and wherein the turn-off switch of the high-side transistor is configured to prevent parasitic turn on at negative currents and prevent the high-side transistor from entering avalanche during continuous mode.