The A8909CLB is a three-phase brushless, back-EMF sensing, spindle-motor driver that integrates analog bipolar, analog and digital CMOS control functions, and DMOS power outputs on a single monolithic chip. It provides complete back-EMF sensing, commutation control, and drive of a spindle motor, and provides for an orderly spindown in the event of supply-voltage removal. Energy for retracting the heads is regenerated from the spinning motor, while a controlled delay allows for a full retract before dynamic braking. The pulse-width modulation system and power DMOS outputs provide control of high currents with minimum power dissipation in the chip, and minimal average power supply currrent.