3964
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
3964
Designed for pulse-width modulated (PWM) current control of
bipolar stepper motors, the A3964SB and A3964SLB are capable of
continuous output currents to
鹵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鈥檚
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.
Data Sheet
29319.28*
DUAL FULL-BRIDGE PWM MOTOR DRIVER
A3964SLB
OUT
1B
SENSE
1
OUT
1A
LOAD
SUPPLY
GROUND
GROUND
V
REF(IN)
RC
1
PHASE
1
ENABLE
1
1
2
3
4
5
6
7
9
8
V
BB
V
CC
1
2
20
19
18
17
16
15
14
OUT
2B
SENSE
2
OUT
2A
LOGIC
SUPPLY
GROUND
GROUND
V
REF(OUT)
RC
2
PHASE
2
ENABLE
2
PWM 2
13
胃
2
12
11
9
10
胃
1
PWM 1
Dwg. PP-047-1
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V
BB
. . . . . . . . .
33 V
Output Current, I
OUT
(10
碌s)
. . . . . .
鹵
1.0 A*
(continuous) . . . . . . . . . . . . .
鹵
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藲C to +85藲C
Junction Temperature, T
J
. . . . . . .
+150藲C鈥?/div>
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . .
-55藲C to +150藲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藲C.
鈥?Fault conditions that produce excessive junction
temperature will activate the device鈥檚 thermal shutdown
circuitry. These conditions can be tolerated but should
be avoided.
FEATURES
s
s
s
s
s
s
s
鹵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
Always order by complete part number:
Part Number
A3964SB
A3964SLB
Package
24-Pin DIP
20-Lead Wide-Body SOIC
1
2
3
4
5
6
7
8
9
10
