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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
μ
PROCESSOR
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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