SENSING A BACK ELECTROMOTIVE FORCE OF A MOTOR

摘要

An apparatus includes a controller and a comparator. The controller generates pulse width modulation (PWM) signals to drive stator windings of a brushless direct current (BLDC) motor in a commutation sequence such that one of the stator windings at a given time is open; and generates a tracking signal synchronized to the PWM signals and indicative of times when a leakage current is present in the open stator winding. The comparator senses when a back electromotive force of the open stator winding has an associated zero crossing. The sensing by the comparator is selectively enabled and disabled by the tracking signal.

主权项

1. A method comprising:
using a processing core to regulate at least one characteristic of a first signal used to drive a first stator winding of a brushless direct current (BLDC) motor; using a peripheral component to generate a tracking signal in response to the first signal, the tracking signal indicating times to sense a back electromotive force of a second stator winding of the BLDC motor; and sensing the back electromotive force in response to the tracking signal.