Fully digital control and drive combo IC with on-board DSP for disk mass storage device

摘要

A combo device for driving and controlling a rotation motor and a voice coil motor of a disk mass storage drive comprises a digital signal processor carrying out a plurality of functions, a memory, a bank of input/output registers, memory address decoding circuits, a circuit controlling and driving a multiphase motor that rotates the disk, a timing block, an output stage driving a "voice coil" motor for positioning a swinging arm carrying at least a read/write head, controlled in switched mode by a generator (PSM GENERATOR) of two control phases of variable duty-cycle, a duty-cycle control loop comprising a current sensing circuit and a control loop of the position of said arm comprising a speed detection circuit. The two control loops are digitally implemented by the digital signal processor (DSP) in function of digital data representing the current flowing in the winding of the "voice coil" motor and of the instant speed of said "voice-coil" motor generated by the speed detection circuit.