The A8983CJT provides for complete spindle and voice coil power electronics for small form-factor HDDs (hard disk drives). The large scale integration and use of advanced DABiC (digital/analog-BiCMOS) merged technologies result in minimum power dissipation, minimum operating voltage, and minimum external components.

The spindle driver system incorporates a three-phase MOS power driver and a back-EMF sensing motor commutation scheme. A patented circuit eliminates the need for an external current-sense resistor, achieving additional headroom. Intrinsic ground clamp and flyback diodes are also provided.
The voice-coil system incorporates a MOS H-bridge driver, sense amplifier, error amplifier, and programmable retract circuitry.
The A8983CJT is supplied in a 64-lead low-profile quad flatpack for surface-mount applications.

FEATURES
Voice Coil Motor Driver:
■ Low rDS(on) MOS Outputs
■ Zero Deadband
■ Externally Determined Transconductance, with Hi/Lo Configuration Switched via Serial Port
■ Current Sensing with External Series Sense Resistor
■ Serial Port Programmable Actuator Retract Circuitry
■ Retract Circuitry Functional to 1.7 V Spindle BEMF

Spindle Motor Controller/Driver:
■ Low rDS(on) MOS Outputs
■ Back-EMF Circuitry Eliminates Hall-Effect Sensors
■ Adaptive Commutation Delay Programmable via Serial Port
■ Programmable Slew Rate (soft switching) Eliminates Snubbers
■ Intrinsic Ground Clamp and Flyback Diodes
■ Patented Lossless Current Sensing Eliminates Need for External Current-Sense Resistor
■ Externally Determined Transconductance, with Hi/Lo Configuration Switched via Serial Port
■ Forward or Reverse Torque Serial Port Bit Allows Improved Speed Disturbance Performance
■ Dynamic Braking with User Delay, Activated by Undervoltage or Serial Port Command
■ Power-On-Reset Generator for Power Up or Power Loss with User-Defined Delay
■ Chip Powers Up in Sleep Mode for Minimum Power Dissipation
■ External 2 MHz System Clock, or Internal Serial Port Trimmed 2 MHz Clock
■ System Diagnostics
■ Uncommitted Op-amp

Energy Manager:
■ 3.0 V to 5.5 V Operation
■ DC-to-DC Converter Maintains rDS(on) Performance at Low Supply
■ Independent Power-Down (Sleep) Modes for all Functional Blocks
■ Efficient Active Regeneration Supplies Power During Retract
■ Supply Under-Voltage Fault Monitor with Adjustable Trip Point