CMOS disk drive motor control circuit having back-EMF blocking circuitry

摘要

A CMOS disk drive motor control circuit which has back-EMF blocking circuitry for preventing the back-EMF from being dissipated when power is removed from the disk drive motor. The back-EMF provides an alternate power source for parking the read/write head. The circuit is fabricated as a single CMOS integrated circuit which is coupled between a power supply and the disk drive motor. The circuit also includes disk drive head parking circuitry and voltage regulator circuitry.