Patent attributes
A control unit for controlling commutation of a brushless direct current (BLDC) motor provided. The control unit controls high-side and low-side switches arranged between a power source and the motor and configured as a three-phase bridge to commutate the motor. The control unit is configured to provide drive signals to drive each of the high-side and low-side switches to control, for each phase of the bridge, a pulse-width modulation (PWM) of one of the high-side or low-side switches. For each phase of the bridge, immediately following a first cycle ending with a falling edge of the drive signal for one of the high-side or low-side switches, the control unit introduces a special commutation edge pulse in the drive signal of the other of the high-side or low-side switches to shunt the current from the motor before turning both the high-side and the low-side switches off during a second cycle.
