A first input of a differential circuit is coupled to a coil tap for a first phase of a multi-phase brushless DC motor. The first phase is associated with an electrically floating coil. A second input of the differential circuit is coupled to a virtual center tap. A divider circuit is coupled between coil taps for other phases of the multi-phase brushless DC motor to define a virtual center tap. The other phases are phases actuated for motor operation when the first phase is electrically floating. The coil tap for the first phase is electrically isolated from the virtual center tap. The differential circuit performs a comparison of the voltage at the coil tap for the first phase to the voltage at the virtual center tap to generate a back EMF signal.