Patent ID: 8569983

Claim:
A motor driving apparatus comprising: a multiphase DC motor including a plurality of multiphase coils; an output stage including: a plurality of power elements coupled to the multiphase coils and which supply output voltages to the multiphase coils, and a predriver coupled to the power elements and which supplies drive voltages to the power elements; a resistor coupled to the power elements and which detects a current flowing through the power elements; a supply current detector which includes an ADC and a digital filter and which detects a voltage signal produced across the resistor as a supply current, using the ADC and the digital filter; and an output controller which generates a PWM signal with a frequency lower than a sampling frequency of the ADC so that the current detected by the supply current detector conforms to a current command for controlling a motor revolving speed, and transfers the PWM signal to the output stage.