US 6,208,185 B1 · High performance active gate drive for IGBTs

Abstract

An active drive circuit for high power IGBTs provides optimized switching performance for both turn-on and turn-off by incorporating a three-stage action to improve performance characteristics. The gate drive circuit includes a semiconductor switch such as a MOSFET connected in series with a low resistance gate turn-on resistor between the supply line and the gate input line, and a parallel connected bipolar transistor. During the first and third stages of turn-on, the MOSFET switch is turned on to provide rapid charging of the gate, whereas during the second stage the bipolar transistor is turned on to provide a controlled level of current charging of the gate. Similarly, a switch such as an MOSFET is connected in series with a low resistance gate turn-off resistor between the turn-off supply voltage line and the gate input line, and a bipolar transistor is connected in parallel therewith across the supply line and the gate input line. During the first and second stages of turn-off, the MOSFET switch is turned on to provide rapid discharging of the gate whereas during the second stage the bipolar transistor is turned on to provide a controlled level of discharge current from the gate.

Claims47

Dependent claims

A gate drive circuit for IGBTs comprising:

(a) turn-on switch means for providing low resistance rapid charging of the gate of an IGBT;
(b) turn-on controlled current means for providing controlled current charging of the gate of the IGBT;
and
(c) means for turning on the turn-on switch means to provide low resistance rapid charging of the gate of an IGBT during a first turn-on stage after receipt of a main command turn-on signal, means for turning on the turn-on controlled current means to provide controlled current charging of the gate of the IGBT during a second turn-on stage that follows the first turn-on stage, and means for turning on the turn-on switch means to provide rapid low resistance final charging of the gate of the IGBT to a turn-on voltage supply level during a third turn-on stage that follows the second turn-on stage and for maintaining the turn-on supply voltage level at the gate while the main turn-on signal is present.

1 more element

A gate drive circuit for IGBTs comprising:

(a) turn-on switch means for providing low resistance rapid charging of the gate of an IGBT;
(b) turn-on controlled current means for providing controlled current charging of the gate of the IGBT;
(c) turn-off switch means for providing low resistance rapid discharging of the gate of the IGBT;
(d) turn-off controlled current means for providing controlled current discharging of the gate of the IGBT;
and
(e) means for turning on the turn-on switch means to provide low resistance rapid charging of the gate of an IGBT during a first turn-on stage after receipt of a main turn-on signal;
means for turning on the turn-on controlled current means to provide controlled current charging of the gate of the IGBT during a second turn-on stage that follows the first turn-on stage;
means for turning on the turn-on switch means to provide rapid low resistance final charging of the gate of the IGBT to a turn-on voltage supply level during a third turn-on stage that follows the second turn-on stage and for maintaining the turn-on supply voltage level at the gate while the main turn-on signal is present;
means for turning off the turn-on switch means and for turning on the turn-off switch means to provide low resistance rapid discharging of the gate of the IGBT during a first turn-off stage after receipt of a main turn-off signal;
means for turning on the turn-off controlled current means to provide controlled current discharging of the gate of the IGBT during a second turn-off stage that follows the first turn-off stage;
and means for turning on the turn-off switch means to provide rapid low resistance discharging of the gate of the IGBT to a turn-off voltage supply level during a third turn-off stage that follows the second turn-off stage and for maintaining the turn-off voltage level at the gate while the main turn-off signal is present.

8 more elements

A gate drive turn-on and turn-off circuit for IGBTs comprising:

(a) a turn-on MOSFET switch and a gate turn-on resistor connected in series between a turn-on supply voltage line and a gate input line;
(b) a turn-on bipolar transistor connected between the turn-on supply voltage line and the gate input line in parallel with the turn-on MOSFET switch and the gate turn-on resistor;
(c) a turn-off MOSFET switch and a gate turn-off resistor connected in series between a turn-off supply voltage line and the gate input line;
and
(d) a turn-off bipolar transistor connected between the turn-off supply voltage line and the gate input line in parallel with the turn-off MOSFET switch and the gate turn-off resistor;
whereby control signals may be provided to the turn-on and turn-off MOSFET switches and the turn-on and turn-off bipolar transistors to provide low resistance gate charging and discharging stages through the MOSFET switches and controlled current gate charging and discharging stages through the bipolar transistors.

3 more elements

Dependencies are inferred from the claim text.

High performance active gate drive for IGBTs

Life of this patent

High performance active gate drive for IGBTs

Life of this patent

Abstract

Claims47