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L7250

July 2001

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

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12V & 5V (±10%) OPERATION

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REGISTER BASED ARCHITECTURE

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3 WIRE SERIAL COMMUNICATION

INTERFACE UP TO 33 MHZ

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BCD TECHNOLOGY

Spindle Motor Controller

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INTERNAL POWER DEVICE 0.9 OHM MAX

VALUE @ 125°C (SINK+SOURCE)

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2.5A PEAK CURRENT CAPABILITY

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ST SMOOTHDRIVE SINUSOIDAL PWM

COMMUTATION

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DEDICATED ADC FOR POWER SUPPLY

VOLTAGE COMPENSATION

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SPINDLE CURRENT LIMITING VIA FIXED

FREQUENCY PWM OF SPINDLE POWER

OUTPUTS AT THE SMOOTHDRIVE PWM

RATE

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SYNCHRONOUS RECTIFICATION DURING

PWM TO REDUCE POWER DISSIPATION

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CURRENT SENSING VIA EXTERNAL

CURRENT SENSE RESISTOR

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INDUCTIVE SENSE POSITION START UP

DRIVEN BY

µPROCESSOR

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SPINDLE BRAKING DURING POWER DOWN

CONDITION

Voice Coil Motor Driver with Ramp Load/Unload

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INTERNAL POWER DEVICE 0.9 OHM MAX

VALUE @ 125°C (SINK+SOURCE)

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2A PEAK CURRENT CAPABILITY

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15 BIT LINEAR DAC FOR CURRENT

COMMAND, WITH INTERNAL REFERENCE

VOLTAGE

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SENSE AMPLIFIER GAIN SWITCH

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CLASS AB OUTPUT STAGE WITH ZERO

DEAD-BAND AND MINIMAL CROSSOVER

DISTORTION

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RAMP LOAD AND UNLOAD CAPABILITY AS

WELL AS CONSTANT VOLTAGE RETRACT

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EXTERNAL CURRENT SENSE RESISTOR IN

SERIES WITH MOTOR.

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HIGH CMRR (>70DB) AND PSRR (>60DB)

SENSE AMP

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EXTERNAL CURRENT CONTROL LOOP

COMPENSATION

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HIGH BANDWIDTH VCM CURRENT

CONTROL LOOP CAPABILITY

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HIGH PSRR, LOW OFFSET, LOW DRIFT GM

LOOP

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VCM VOLTAGE MODE, CONTROLLED BY

VCM DAC

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GM LOOP OFFSET CALIBRATION SCHEME

INCLUDES A COMPARATOR ON THE

ERROR AMP

Auxiliary Functions

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3.3V AND 1.8V LINEAR REGULATOR

CONTROLLER

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NEGATIVE VOLTAGE REGULATOR

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INTERNAL ISOFET 0.1 OHM @125C

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POWER MONITOR OF 12V, 5V, 3.3V AND

1.8V

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SHOCK SENSOR CIRCUIT TAKES INPUTS

FROM PIEZO OR CHARGING ELEMENT

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10 BIT ADC WITH 4 MUXED INPUTS

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THERMAL SENSE CIRCUIT AND OVER

TEMPERATURE SHUT DOWN

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CHARGE PUMP BOOST VOLTAGE

GENERATOR FOR HIGH SIDE GATE DRIVE

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ANALOG PINS AVAILABLE TO ENTER

SIGNALS TO BE CONVERTED BY THE

INTERNAL ADC

DESCRIPTION

L7250 is a power IC for driving the SPINDLE and

VCM motors, suitable for 5V & 12V application. The

spindle system includes integrated power FETs

which are driven using ST's Smoothdrive pseudo-si-

nusoidal commutation technology. The voice coil mo-

tor (VCM) system includes integrated power FETs,

as well as ramp load and unload capability. Linear

3.3V and1.8V voltage regulators are included, as well

as a negative regulator.

Power monitoring of VCC5, VCC12, and of the two

positive voltage regulators is also included.L7250

uses a 3 wire serial interface: S_DATA, S_CLK and

S_ENABLE

TQFP64

ORDERING NUMBER: L7250

PRODUCT PREVIEW

5V & 12V SPINDLE AND VCM MOTORS DRIVER