Motor control circuit of data reproduction apparatus

摘要

The invention relates to a motor control circuit of a data reproduction apparatus, which drives a disk motor to reproduce a data signal recorded together with a sync signal on a recording medium so as to control the disk motor in accordance with a reproduced sync signal. The frequency and phase components of the reproduced sync signal are detected, and first and second motor control signals are produced in accordance with frequency and phase detection signals, respectively. A control circuit detects whether or not the frequency detection signal falls within a predetermined range. If it is determined that the frequency detection signal does not fall within the predetermined range, the second motor control signal is kept at a predetermined value.