Gate driver controller and associated discharge method

An apparatus to control a motor having first, second and third motor-winding inductors, the apparatus comprising:

• an inverter circuit having a first output coupled to the first motor-winding inductor, a second output coupled to the second motor-winding inductor and a third output coupled to the third motor-winding inductor, the inverter circuit coupled to a capacitor and configured to output alternating current in response to energy stored in the capacitor, the inverter circuit comprising:
• a plurality of power transistors, a first portion of the plurality of power transistors coupled to the first motor-winding inductor, a second portion of the plurality of power transistors coupled to the second motor-winding inductor and a third portion of the plurality of power transistors coupled to the third motor-winding inductor;
• and
• a plurality of gate drivers, each of the plurality of gate drivers coupled to a corresponding power transistor of the plurality of power transistors and configured to switch the corresponding power transistor on or off;
• a controller coupled to the plurality of gate drivers and configured to control the plurality of gate drivers to turn on and off portions of the plurality of power transistors to control the motor;
• and
• wherein the controller is operable in a first operating mode and a second operating mode to cause the inverter to dissipate the stored energy by:
• activating a first power transistor and a second power transistor of the plurality of power transistors and deactivating the remaining plurality of power transistors to dissipate, in the first mode of operation, the energy stored in the capacitor using the first and second motor-winding inductors;
• and
• activating the second power transistor of the plurality of power transistors and deactivating the remaining plurality of power transistors to dissipate, in the second operating mode, energy stored in the first and second motor-winding inductors using the second power transistor and a body diode of a third power transistor of the plurality of power transistors.