L6246 Datasheet, PDF (1/12 Pages) STMicroelectronics – 12V VOICE COIL MOTOR DRIVER

L6246
12V VOICE COIL MOTOR DRIVER
12V (±10%) OPERATION
3A MAXIMUM CURRENT CAPABILITY
0.3Ω MAXIMUM ON RESISTANCE OF EACH
POWER DMOS AT A JUNCTION TEM-
PERATAURE OF 25°C
CLASS AB POWER AMPLIFIERS
LOGIC AND POWER SUPPLY MONITOR
POWER ON RESET
PARKING FUNCTION WITH SELECTABLE
RETRACT VOLTAGE AND DYNAMIC BRAKE
BEFORE PARKING
ENABLE FUNCTION
GATE DRIVER FOR EXTERNAL BLOCKING
N-MOSFET
OVERTEMPERATURE PROTECTION
OVERTEMPERATURE WARNING OUTPUT
PQFP44 PACKAGE
MULTIPOWER BCD TECHNOLOGY
PQFP44 (10x10)
DESCRIPTION
The voice coil driver L6246 is a linear power am-
plifier designed to drive single phase bipolar DC
motors for hard disk drive applications. The de-
vice contains a selectable transconductance loop,
which allows high precision for head positioning.
The power stage is composed of 2 power amplifi-
ers, in AB class, with 4 DMOSs, with Rdson of
0.5Ω (Sink+Source) maximum, in a H-bridge con-
figuration. Drive voltage for the upper DMOS
FETs is provided by a charge pump circuit to en-
sure low Rdson.
Automatic brake and parking of the head actuator
is performed by logic or when a failure condition
is detected by power supply monitors. An external
resistor programs the parking voltage that en-
ables the head retract. In addition, a 5V stable
output is provided for the external usage, and a
gate driver circuit enables an external power sup-
ply isolation N-MOSFET.
This device is built in BCD II technology allowing
dense digital circuitry to be combined with high
power bipolar power devices and is assembled in
PQFP44.
February 1998
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