The A8905CLB isw a three-phase brushless dc motor controller/ driver for use with CD-ROM or DVD drives. The three half-bridge outputs are low on-resistance n-channel DMOS devices capable of driving up to 1.25 A. The A8905CLB provides complete, reliable, self-contained back-EMF sensing motor startup and running algorithms. A programmable digital frequency-locked loop speed control circuit together with the linear current control circuitry provides precise motor speed regulation.