Monitoring control signals of power switches in a half bridge for motor control or other applications

A method of controlling a high-side power switch and a low-side power switch arranged in a half bridge configuration, the method comprising:

• driving a gate of the high-side power switch based on high-side pulse modulation (PM) signals;
• driving a gate of the low-side power switch based on low-side PM signals;
• and
• monitoring the high-side PM signals and the low-side PM signals,
• wherein the high-side PM signals and the low-side PM signals are configured to turn the high-side power switch and the low-side power switch ON and OFF in a complementary fashion, and
• wherein monitoring includes:
• detecting one or more absences of either the high-side PM signals or the low-side PM signals;
• and
• generating a fault signal in response to detecting the one or more absences.

A system comprising:

• a three-phase electric motor;
• a plurality of half bridge circuits each comprising a high-side power switch and a low-side power switch arranged in a half bridge configuration, wherein each of the half bridge circuits controls a respective phase of the three-phase electric motor;
• for each of the plurality of half bridge circuits, a respective driver circuit configured to control the high-side power switch and the low-side power switch;
• and
• a processor configured to generate control signals for each of the respective driver circuits, wherein:
• each of the respective driver circuits includes:
• a logic circuit configured to monitor high-side pulse modulation (PM) signals and low-side PM signals,
• wherein the high-side PM signals and the low-side PM signals are configured to turn the high-side power switch and the low-side power switch ON and OFF in a complementary fashion, and
• wherein the logic circuit is configured to detect one or more absences of either the high-side PM signals or the low-side PM signals and generate a fault signal in response to detecting the one or more absences.