Texas Instruments Incorporated
Optimizing comparator operation for a varying DC component input

Abstract:

In one embodiment, an apparatus includes a different amplifier. A node in the apparatus receives a motor-current signal and an output of the differential amplifier. The motor-current signal represents a motor current of a DC brush motor. Moreover, a first input of the differential amplifier is coupled to a node. The apparatus also includes a low-pass filter with an input receiving a motor-current signal and an output coupled to a second input of the differential amplifier. The apparatus additionally includes a comparator with a first input coupled to the output of the differential amplifier and a second input coupled to a referential voltage.