A3988
Quad DMOS Full Bridge PWM Motor Driver
Features and Benefits
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36 V output rating
4 full bridges
Dual stepper motor driver
High current outputs
3.3 and 5 V compatible logic supply
Synchronous rectification
Internal undervoltage lockout (UVLO)
Thermal shutdown circuitry
Crossover-current protection
Low profile QFN package
Description
The A3988 is a quad DMOS full-bridge driver capable of
driving up to two stepper motors or four dc motors. Each
full-bridge output is rated up to 1.2 A and 36 V. The A3988
includes fixed off-time pulse width modulation (PWM) current
regulators, along with 2- bit nonlinear DACs (digital-to-analog
converters) that allow stepper motors to be controlled in full,
half, and quarter steps, and dc motors in forward, reverse, and
coast modes. The PWM current regulator uses the Allegro
®
patented mixed decay mode for reduced audible motor noise,
increased step accuracy, and reduced power dissipation.
Internal synchronous rectification control circuitry is provided
to improve power dissipation during PWM operation.
Protection features include thermal shutdown with hysteresis,
undervoltage lockout (UVLO) and crossover current protection.
Special power up sequencing is not required.
The A3988 is supplied in two packages, EV and JP, with
exposed power tabs for enhanced thermal performance. The
EV is a 6 mm x 6 mm, 36 pin QFN package with a nominal
overall package height of 0.90 mm. The JP is a 7 mm × 7 mm
48 pin LQFP. Both packages are lead (Pb) free, with 100%
matte tin leadframe plating.
Packages
Package EV, 36 pin QFN
0.90 mm nominal height
with exposed thermal pad
Package JP, 48 pin LQFP
with exposed thermal pad
Approximate scale
0.1
μF
50 V
VCP
CP1
CP2
0.1
μF
50 V
VBB1
VBB2
100
μF
50 V
V
MOTOR
32 V
0.22
μF
50 V
PHASE1
I01
I11
PHASE2
Microprocessor
I02
I12
PHASE3
I03
I13
PHASE4
I04
I14
VREF1
V
REF
VREF2
VREF3
VREF4
VDD
V
DD
3.3 V
OUT1A
OUT1B
A3988
OUT2A
OUT2B
OUT3A
OUT3B
OUT4A
OUT4B
SENSE2
R
S2
SENSE1
R
S1
SENSE3
R
S3
SENSE4
R
S4
Bipolar Stepper Motors
Figure 1. Typical application circuit
A3988DS, Rev. 5
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
