Motor driving circuit and electronic apparatus using the same

摘要

A motor driving circuit for driving a motor, includes: a detecting circuit configured to detect a detection signal indicative of a current state of the motor; a command value generating unit configured to generate a command value indicative of a target state of the motor; an error amplifier configured to generate an error signal by amplifying an error between the detection signal and the command value; a pulse width modulator configured to generate a pulse signal; and an output circuit. The command value generating unit is configured to provide a variation to the command value.

主权项

1. A motor driving circuit for driving a motor, comprising:
a detecting circuit configured to detect a detection signal indicative of a current state of the motor; a command value generating unit configured to generate a command value indicative of a target state of the motor; an error amplifier configured to generate an error signal by amplifying an error between the detection signal and the command value; a pulse width modulator configured to generate a pulse signal having a duty cycle corresponding to the error signal; and an output circuit configured to apply a switching voltage having a duty cycle corresponding to the pulse signal across the motor, wherein the command value generating unit is configured to provide a variation to the command value, wherein the command value generating unit includes:
a set voltage generating part configured to generate a set voltage; anda first D/A converter configured to generate the command value, the first D/A converter having a reference voltage terminal receiving the set voltage and an input terminal receiving a digital value representing the command value, wherein the set voltage generating part is configured to provide a variation to the set voltage, and wherein the set voltage generating part modulates the set voltage with a predetermined frequency.