Paralleling power switches using a differential mode choke in the gate drive loop

A power module, comprising:

• a first power switch having a first gate;
• a second power switch paralleled with the first power switch and having a second gate;
• a terminal coupled to receive a gate drive signal from a gate driver to drive both the first gate and the second gate;
• a first conduction path to couple the gate drive signal to the first gate;
• a second conduction path to couple the gate drive signal to the second gate;
• and
• a distribution choke to distribute the gate drive signal to the first and second power switches, the distribution choke having a first winding disposed in the first conduction path and a second winding disposed in the second conduction path, the distribution choke coupled in a differential mode.

A device comprising:

• a first IGBT having a first gate;
• a second IGBT coupled in parallel with the first IGBT and having a second gate;
• an IGBT driver to output a gate drive signal to drive both the first gate and the second gate;
• a first conduction path to couple the gate drive signal to the first gate;
• a second conduction path to couple the gate drive signal to the second gate;
• and
• a distribution choke to distribute the gate drive signal to the first and second IGBTs, the distribution choke having a first winding disposed in the first conduction path and a second winding disposed in the second conduction path, the distribution choke coupled in a differential mode.

A power switch module comprising:

• a first voltage-controlled power switch having a gate and a pair of main terminals;
• a second voltage-controlled power switch having a gate and a pair of main terminals, wherein one of the main terminals of each of the first and second voltage-controlled power switch are coupled together;
• a differential choke comprising a first winding and a second winding;
• and
• a power switch driver comprising a gate drive signal output coupled by a first conduction path to the gate of the first voltage-controlled power switch and by a second conduction path to the gate of the second voltage-controlled power switch,
• wherein the first conduction path comprises the first winding;
• wherein the second conduction path comprises the second winding;
• wherein a difference in impedance of the first conduction path between the gate drive signal output and the first winding and impedance of the second conduction path between the gate drive signal output and the second winding is smaller than a difference in impedance of the first conduction path between the first winding and the gate of the first voltage-controlled power switch and impedance of the second conduction path between the second winding and the gate of the second voltage-controlled power switch.

A power switch module comprising:

• at least two paralleled power switches each having a respective control terminal;
• a common power switch driver comprising a single gate drive signal output coupled to each of the control terminals of the paralleled power switches by a respective conduction path;
• one or more chokes each comprising a pair of windings, the windings of each choke disposed in different of the conduction paths in a differential mode, wherein at least one of the conduction paths includes at least two windings;
• and
• a plurality of capacitances coupled between the control terminals of the power switches.