A4987
DMOS Dual Full-Bridge PWM Motor Driver
With Overcurrent Protection
Features and Benefits Description
Low R outputs The A4987 is a dual DMOS full-bridge stepper motor driver
DS(ON)
Internal mixed current decay mode with parallel input communication and overcurrent protection.
Synchronous rectification for low power dissipation Each full-bridge output is rated up to 35 V and 1 A. The A4987
Internal UVLO includes fixed off-time pulse width modulation (PWM) current
Crossover-current protection regulators, along with 2- bit nonlinear DACs (digital-to-analog
3.3 and 5 V compatible logic supply converters) that allow stepper motors to be controlled in full,
Thin profile QFN and TSSOP packages half, and quarter steps. The PWM current regulator uses the
Thermal shutdown circuitry Allegro patented mixed decay mode for reduced audible
Short-to-ground protection motor noise, increased step accuracy, and reduced power
Shorted load protection dissipation.
Low current Sleep mode, < 10 A
Internal synchronous rectification control circuitry is provided
to improve power dissipation during PWM operation.
Packages:
The outputs are protected from shorted load and short-to-
24-contact QFN
ground events, which protect the driver and associated circuitry
4 mm 4 mm 0.75 mm
from thermal damage or flare-ups. Other protection features
Approximate size
(ES package)
include thermal shutdown with hysteresis, undervoltage lockout
(UVLO) and crossover current protection. Special power-up
sequencing is not required.
The A4987 is supplied in two packages, a 24-contact QFN (ES)
24-pin TSSOP
and a 24-pin TSSOP (LP). Both packages have exposed thermal
with exposed thermal pad
pads for enhanced thermal performance. The 24-contact ES is
(LP Package)
4 mm 4 mm, with a nominal overall package height of 0.75
mm. The 24-pin LP is a TSSOP with 0.65 pitch and an overall
package height of 1.2 mm. Both packages are lead (Pb) free,
with 100% matte tin leadframe plating.
Typical Application Diagram
V 0.1 F0.1 F
DD
0.22 F
VREG ROSC CP1 CP2 VCP
VBB1
0.22 F
VDD 100 F
VBB2
Microcontroller or
OUT1A
Controller Logic
SLEEP
A4987
OUT1B
IN01
SENSE1
IN02
PH1
IN11
OUT2A
IN12
OUT2B
PH2
SENSE2
VREF
GND GND
4987-DS, Rev. 5DMOS Dual Full-Bridge PWM Motor Driver
A4987
With Overcurrent Protection
Selection Guide
Part Number Package Packing
A4987SESTR-T 24-pin QFN with exposed thermal pad 1500 pieces per 7-in. reel
A4987SLPTR-T 24-pin TSSOP with exposed thermal pad 4000 pieces per 13-in. reel
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Units
Load Supply Voltage V 35 V
BB
Output Current I 1 A
OUT
Logic Input Voltage V 0.3 to 5.5 V
IN
Logic Supply Voltage V 0.3 to 5.5 V
DD
Motor Outputs Voltage 2.0 to 37 V
Sense Voltage V 0.5 to 0.5 V
SENSE
Reference Voltage V 5.5 V
REF
Operating Ambient Temperature T Range S 20 to 85 C
A
Maximum Junction T (max) 150 C
J
Storage Temperature T 55 to 150 C
stg
Allegro MicroSystems, LLC
2
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com