Patent ID: 7109742

Claim:
A method for measuring current by a single sensor for two motor phases, drive current to the two phases switched by a first set of upper and lower switches to drive a first phase of a motor and a second set of upper and lower switches to drive a second phase of a motor, with the switches being controlled by a plurality of pulse width modulation signals, the method comprising the steps of: reading a duty cycle of each drive current to a respective winding; configuring the pulse width modulation signals to provide at least one timing window wherein at least of one of the windings of the motor is being driven while the other winding is not being driven, and to provide a relative timing offset of approximately one-half cycle between the pulse width modulation signals driving a first winding and a second winding of the motor; gating the first and second set of switches using the configured pulse width modulation signals from the configuring step; and sampling the current of the at least one of the windings during the at least one timing window.