8983

SPINDLE & VOICE-COIL

ACTUATION MANAGER/DRIVER

DISCONTINUED

PRODUCT

—

FOR

REFERENCE

ONL

Y

Dwg. PP-060

8983

SPINDLE & VOICE-COIL

ACTUATION MANAGER/DRIVER

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 pat-

ented 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 spindle and voice-coil control functions are supplemented by

BEMF to protect the heads and the data disk during system power

supply failure. Active regeneration of spindle BEMF provides nearly

lossless conversion of spindle BEMF into supply voltage to operate the

voice coil motor for parking the heads. A dc-to-dc converter provides for

modes and latched fault states for undervoltage and serial port com-

manded fault.

The A8983CJT is supplied in a 64-lead low-profile quad flatpack for

surface-mount applications.

FEATURES

Voice Coil Motor Driver:

s Low r

s Zero Deadband

s Externally Determined Transconductance, with Hi/Lo

Configuration Switched via Serial Port

s Current Sensing with External Series Sense Resistor

s Serial Port Programmable Actuator Retract Circuitry

s Retract Circuitry Functional to 1.7 V Spindle BEMF

Spindle Motor Controller/Driver:

s Low r

s Back-EMF Circuitry Eliminates Hall-Effect Sensors

s Adaptive Commutation Delay Programmable via Serial Port

s Programmable Slew Rate (soft switching) Eliminates Snubbers

s Intrinsic Ground Clamp and Flyback Diodes

Output current rating may be restricted to a value

determined by system concerns and factors.

These include: system duty cycle and timing,

ambient temperature, and use of any heatsinking

and/or forced cooling.

ABSOLUTE MAXIMUM RATINGS

at T

Load Supply Voltage, V

7.0 V

Spindle Output Current, I

Voice-Coil Output Current, I

Logic Supply Voltage V

6.0 V

Operating Temperature Range,

T