3965
1

Designed for Pulse Width Modulated (PWM) current control of low
voltage stepper motors, the A3965S is capable of output currents to ± 500 mA
and operating voltages to 20 V.
The A3965 is particularly attractive for low power or battery
operated motors where minimal power consumption is desired. A SLEEP
mode disables all circuitry and typically draws less than 1µA supply current
from motor and logic supply. During operation the fixed frequency ON
pulses of each H-bridge are 180 degrees out of phase to minimize the peak
demand required of the motor supply allowing savings in size and cost of
external power supply components.
PHASE and ENABLE input terminals are provided for use in
controlling the speed and direction of a stepper motor with externally applied
PWM control signals.
Internal circuit protection includes thermal shutdown with
hysteresis, undervoltage monitoring of V
DD
and charge pump, and crossover
current protection. Special power up sequencing is not required.
The A3965 is supplied in a 24-lead plastic SOIC with a copper
batwing tab (suffix ‘LB’).
FEATURES
„ ±500 mA, 20 V Output Rating
„ 2.85 to 5.5V Logic Supply Operation
„ Sleep Mode for Minimum Power Consumption
„ Fixed Frequency PWM
„ Offset On Pulses to Minimize Peak Supply Transient Currents
„ Internal UVLO and Thermal Shutdown Circuitry
„ Crossover-Current Protection
ABSOLUTE MAXIMUM RATINGS
at T
A
= +25°C
Load Supply Voltage, VBB ..........................20 V
Output Current, I
OUT
............................ ±500 mA*
Logic Supply Voltage, V
DD
..........................7.0 V
Logic Input Voltage Range,
V
IN
......................-0.3 V to V
DD
+ 0.3 V
(t
W
<30ns)..................-1.0V to V
DD
+1V
Sense Voltage, V
SENSE
..................................0.5 V
Reference Voltage, V
REF
.................................3 V
Package Power Dissipation (T
A
= +25°C), P
D
A3965SLB........................... 50°C/W**
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.
*Measured with 062" thick FR4, two sided PCB with 1 sq
inch copper area.
PRELIMINARY DATASHEET - 12/4/2002
(Subject to change without notice)
DMOS DUAL FULL-BRIDGE
PWM MOTOR DRIVER