NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a
product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The information
included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor
for any infringements of patents or other rights of third parties which may result from its use.
Recommended Substitutions:
DMOS Dual Full-Bridge PWM Motor Driver
A3965
The A3965 is a fairly unique device within Allegro's portfolio, typically
fitting niche low-voltage, battery-driven stepper motor applications.
Our closest recommended alternatives are:
For customers looking for a stepper motor driver for battery-driven
applications, we recommend the
A3977
, A3982, A3983, or A3984.
The closest device functionally is the
A3966,
if supply current and a
low logic voltage (4.75 to 5.5 V) are not issues.
Date of status change: November 1, 2004
These parts are in production but have been determined to be
NOT FOR NEW DESIGN. This classification indicates that sale of
this device is currently restricted to existing customer applications.
The device should not be purchased for new design applications
because obsolescence in the near future is probable. Samples are no
longer available.
Not for New Design
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 1
A 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 TA = +25C
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 (TA = +25C), P
D
A3965SLB........................... 50
C/W**
Operating Temperature Range,
T
A
................................ -20
C to +85C
Junction Temperature, T
J
......................... +150
C
Storage Temperature Range,
T
S
............................... -55
C to +150C
* 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
3965 DMOS Dual Full Bridge
PWM Motor Driver
3
ELECTRICAL CHARACTERISTICS at T
A
= +25C, V
BB
= 20 V, V
DD
= 3.0 V, V
SENSE
= 0.5 V, f
PWM
< 50KHz (unless
noted otherwise)
Limits
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Output Drivers
Load Supply Voltage Range
VBB
Operating, I
OUT
=
500 mA
6
20
V
During Sleep Mode
0
20
V
Output Leakage Current
I
DSS
V
OUT
= V
BB
<1.0
20
A
V
OUT
= 0 V
<1.0
-20
A
Output On Resistance
R
DSON
Source Driver, I
OUT
= -500 mA
1.2
1.35
Sink Driver, I
OUT
= 500 mA
.75
.9
Source Driver, I
OUT
= -500 mA; VBB=6V
1.3
1.5
Sink Driver, I
OUT
= 500 mA, VBB=6V
.85
1.0
Body Diode Forward Voltage
V
F
Source Diode, I
F
= -500 mA
1
V
Sink Diode, I
F
= 500mA
1
V
Motor Supply Current
I
BB
f
PWM
< 50 kHz
3.5
7
mA
Charge Pump On, Outputs Disabled
1.5
3
mA
Sleep Mode
10
uA
I
DD
f
PWM
< 50 kHz
4.5
mA
Outputs Off
3.6
mA
Logic Supply Current
Sleep Mode (Inputs below .5V)
<1
10
A
Control Logic
Logic Supply Voltage Range
V
DD
Operating
2.85
5.5
V
Logic Input Voltage
V
IN(1)
V
DD
*.7
V
V
IN(0)
V
DD
*.3
V
Logic Input Current
I
IN(1)
V
IN
= V
DD
*.7
-20
<1.0
20
A
I
IN(0)
V
IN
= V
DD
*.3
-20
<1.0
20
A
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