3964
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
DUAL FULL-BRIDGE PWM MOTOR DRIVER
Data Sheet
29319.28*
A3964SLB
Designed for pulse-width modulated (PWM) current control of
bipolar stepper motors, the A3964SB and A3964SLB are capable of
continuous output currents to ±800 mA and operating voltages to 30 V.
Internal fixed off-time PWM current-control circuitry can be used to
regulate the maximum load current to a desired value. An internal
precision voltage reference is provided to improve motor peak-current
control accuracy. The peak load current limit is set by the user’s
selection of an external resistor divider and current-sensing resistors.
The fixed off-time pulse duration is set by user-selected external
RC timing networks. The capacitor in the RC timing network also
determines a user-selectable blanking window that prevents false
triggering of the PWM current control circuitry during switching transi-
tions. This eliminates the need for two external RC filter networks on
the current-sensing comparator inputs.
For each bridge the PHASE input controls load current polarity by
selecting the appropriate source and sink driver pair. For each bridge
the ENABLE input, when held high, disables the output drivers. Spe-
cial power-up sequencing is not required. Internal circuit protection
includes thermal shutdown with hysteresis, transient-suppression
diodes, and crossover-current protection.
The A3964SB is supplied in a 24-pin plastic DIP with copper heat
sink tabs; A3964SLB is supplied in a 20-lead plastic SOIC with copper
heat sink tabs. The power tabs are at ground potential and need no
electrical isolation.
FEATURES
■ ±800 mA Continuous Output Current Rating
■ 30 V Output Voltage Rating
■ Internal PWM Current Control, Saturated Sink Drivers
■ Internally Generated, Precision 2.5 V Reference
■ Internal Transient-Suppression Diodes
■ Internal Thermal-Shutdown Circuitry
■ Crossover-Current Protection, UVLO Protection
3964
1
V
BB
2
1
2
3
4
5
6
7
9
20
19
18
17
16
15
14
13
12
11
10
9
8
θ
2
θ
1
V
CC
PWM 1
PWM 2
GROUND
GROUND
GROUND
GROUND
PHASE
2
V
REF(OUT)
2
RC
1
RC
V
REF(IN)
PHASE
1
2B
OUT
SENSE
2
2A
OUT
1A
OUT
SENSE
1
1B
OUT
LOAD
SUPPLY
LOGIC
SUPPLY
Dwg. PP-047-1
ENABLE
1
ENABLE
2
Always order by complete part number:
Part Number Package
A3964SB 24-Pin DIP
A3964SLB 20-Lead Wide-Body SOIC
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V
BB
. . . . . . . . . 33 V
Output Current, I
OUT
(10 µs) . . . . . . ±1.0 A*
(continuous) . . . . . . . . . . . . .
±800 mA*
Logic Supply Voltage, V
CC
. . . . . . . . . 7.0 V
Logic Input Voltage Range,
V
IN
. . . . . . . . . . . -0.3 V to V
CC
+ 0.3 V
Sense Voltage, V
S
. . . . . . . . . . . . . . . 1.0 V
Reference Output Current,
I
REF(OUT)
. . . . . . . . . . . . . . . . . . 1.0 mA
Package Power Dissipation,
P
D
. . . . . . . . . . . . . . . . . . . . See Graph
Operating Temperature Range,
T
A
. . . . . . . . . . . . . . . . -20˚C to +85˚C
Junction Temperature, T
J
. . . . . . . +150˚C†
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . . -55˚C to +150˚C
* Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under any set
of conditions, do not exceed the specified current rating
or a junction temperature of 150˚C.
† Fault conditions that produce excessive junction
temperature will activate the device’s thermal shutdown
circuitry. These conditions can be tolerated but should
be avoided.
