Control circuit for spindle motor.

摘要

A control circuit for controlling according to external standard pulses a spindle motor used to rotate a recording disc medium pre-recorded thereon with clock data indicative of angular position thereof. A detecter operates during the rotation of recording disc medium for detecting the clock data and producing successively clock pulses in response to detection of the clock data. A comparator compares phase of the clock pulses with that of the external standard pulses inputted from a standard pulse source outside the control circuit to produce a phase error signal indicative of phase difference between the clock pulses and the standard pulses. A controller controls rotation speed of the spindle motor according to the phase error signal to thereby synchronize the clock pulses to the standard pulses.