GENERAL

5V (+/- 10%) OPERATION.

REGISTER BASED ARCHITECTURE

MINIMUM EXTERNAL COMPONENTS

BICMOS + VERTICAL DMOS (1.5mm)

VCM DRIVER

1.5A DRIVE CAPABILITY

0.9

Ω TOTAL BRIDGE IMPEDANCE AT 25°C

LINEAR MODE

PHASE SHIFT MODULATION (PWM MODE)

INSTANTANEOUS, (GLICH FREE) SWITCH

BETWEEN THE 2 MODES

CLASS AB OUTPUT DRIVERS

ZERO CROSSOVER DISTORSION

14 BIT DAC DEFINE OUTPUT CURRENT

SELECTABLE TRANSCONDUCTANCE

4 PROGRAMMABLE PARKING VOLTAGE

DYNAMIC BRAKE

SPINDLE DRIVER

2.0A DRIVE CAPABILITY

0.8

Ω TOTAL BRIDGE IMPEDANCE AT 25°C

BEMF, INTERNAL OR EXTERNAL, PROC-

ESSING

SENSOR-LESS MOTOR COMMUTATION

PROGRAMMABLE COMMUTATION PHASE

DELAY

LINEAR MODE AND CONSTANT TOFF PWM

OPERATION MODE

INTERNAL FREQUENCY LOCKED LOOP

SPEED CONTROL (FLL)

BEMF RECTIFICATION DURING RETRACT

BUILT-IN ALIGNAMENT&GO START-UP

INDUCTIVE SENSING START UP OPTION

RESYNCHRONIZATION

DYNAMIC & REVERSE BRAKE

CONTROLLABLE OUTPUT SLEW RATE

OTHER FUNCTIONS

5V MONITORING WITH EXTERNAL SET

TRIP POINTS AND HYSTERESIS

POWER UP/DOWN SEQUENCING

LOW VOLTAGE SENSE

3.3V INPUT LOGIC COMPATIBILITY

THERMAL SHUTDOWN AND PRETHERMAL

WARNING

SYSTEM CLOCK WATCHDOG

DESCRIPTION

The L6275 integrates into a single chip both spin-

dle and VCM controllers as well as power stages.

The device is designed for 12V disk drive applica-

tion requiring up to 2.0A of spindle and 1.5A of

VCM peak currents.

A serial port with up to 25 MHz capability provides

easy interface to the microprocessor. A register

controlled Frequency Locked Loop (FLL) allows

flexibility in setting the spindle speed. Integrated

BEMF processing, digital masking, digital delay,

and sequencing minimize the number of external

components required.

Power On Reset (POR) circuitry is included. Upon

detection of a low voltage condition, POR is as-

serted, the internal registers are reset, and spin-

dle power circuitry is tri-stated. The BEMF is recti-

fied providing power for actuator retraction

followed by dynamic spindle braking.

The device is built in BICMOS technology allow-

ing dense digital/analog circuitry to be combined

with a high power DMOS output stage.

This is preliminary information on a new product now in development. Details are subject to change without notice.

April 1999

®

TQFP44 (10x10mm)

ORDERING NUMBER: L6275

L6275

5V DISK DRIVE SPINDLE & VCM, POWER

& CONTROL “COMBO”

PRODUCT PREVIEW

BICMOS TECHNOLOGY

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