A1442
Low Voltage Full Bridge Brushless DC Motor Driver with Hall Commutation and
Soft-Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection
Features and Benefits
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Low voltage operation
¯LEEP
¯¯¯
Reverse voltage protection on VDD and S¯ ¯ ¯ ¯ pins
Output short circuit and thermal shutdown protections
Soft switching algorithm to reduce audible switching
noise and EMI interference
Unidirectional working mode provides motor rotation in
one direction
Hall chopper stabilization technique for precise signal
response over operating range
Sleep mode pin allowing external logic signal enable/
disable to reduce average power consumption
Antistall feature guarantees continuous rotation
Low current consumption sleep mode
Single-chip solution for high reliability
Miniature MLP/DFN package
Description
The A1442 is a full-bridge motor driver designed to drive
low-voltage, brushless dc motors. Commutation of the motor
is achieved by use of a single Hall element sensor to detect the
rotational position of an alternating-pole ring magnet. A high-
density CMOS semiconductor process allows the integration
of all the necessary electronics. This includes the Hall element
sensor, the motor control circuitry, and the full output bridge.
Low-voltage design techniques have been employed to achieve
full device functionality down to low V
DD
values. This fully
integrated single chip solution provides enhanced reliability
(including reverse battery protection and output short circuit
protection) and eliminates the need for any external support
components.
The A1442 employs a soft-switching algorithm to reduce audible
switching noise and EMI interference. A micropower sleep
mode can be enabled by an external signal, to reduce current
consumption for battery management in portable electronic
devices. This feature allows the removal of a FET transistor
for switching the device on and off.
The A1442 is optimized for vibration motor applications in
cellular phones, pagers, electronic toothbrushes, hand-held
video game controllers, and low power fan motors.
The small package outline and low profile make this device
ideally suited for use in applications where printed circuit board
area and component headroom are at a premium. It is available
in a lead (Pb) free, 6 pin MLP/DFN microleadframe package,
with an exposed pad for enhanced thermal dissipation.
Package: 6 pin MLP/DFN (suffix EW)
1.5 mm × 2 mm, 0.40 mm maximum overall height
Approximate scale
Functional Block Diagram
VDD
Reverse Battery
SLEEP
Output
Full Bridge
Active Braking
Control
Q1
Drive Logic
and
Soft Start
Control
Q2
Amp
Q4
Thermal Shutdown
Protection
M
Q3
Power and Sleep
Mode Control
VOUT1
VOUT2
0.1
μF
Stall Detection
Hall
Element
GND
A1442-DSS
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
