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3976
ADVANCED DATASHEET - 02/19/99
(Subject to change without notice)
DUAL FULL BRIDGE
PROTECTED MOTOR DRIVER
The A3976 is designed to drive both windings of a bipolar stepper
motor or bidirectionally control two DC Motors. Both H-Bridges are capable
of continuous output currents of up to +/- 500 mA and operating voltages to
30V. Free wheeling, substrate isolated diodes are included for output transient
suppression when switching motors or other inductive loads. For each bridge
the PHASE input controls load current polarity by selecting the appropriate
source and sink driver pair. The ENABLE input, when held high, enables the
respective output H-bridge. When both ENABLE pins are held low the device
will enter SLEEP mode and consume less than 100µA.
The 3976 is protected to ensure safe operation in harsh operating
environments and was designed specifically for automotive applications.
Protection circuitry will check for open or shorted load, motor lead short to
ground or supply, VBB overvoltage, VCC undervoltage, and thermal
shutdown. If any of these conditions are detected the outputs will be disabled
and fault information will be output to diagnostic pins FAULT1 and FAULT2.
The 3976 is supplied in a choice of two power packages, a 16-lead
plastic DIP with a copper batwing tab (suffix ‘B’), and a 24-lead plastic SOIC
with a copper batwing tab (suffix ‘LB’). In both cases, the power tab is at
ground potential and needs no electrical isolation.
V
BB
1
ENABLE1 2
PHASE1 3
n/c 4
n/c 5
GROUND
6
GROUND
7
n/c
8
OUT1A
9
n/c
10
FAULT1
11
OUT1B
12
24
V
CC
23
ENABLE2
22
PHASE2
21
n/c
20
n/c
A3976KLB
19
GROUND
18
GROUND
17
n/c
16
OUT2A
15
n/c
14
FAULT2
13
OUT2B
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Operating Supply Voltage, V
BB
....................
30 V
Non-Operating Supply Voltage.....................
35 V
Output Current, I
OUT
............................±
500 mA*
±
Logic Supply Voltage, V
CC
..........................
7.0 V
Fault Output Voltage ...................................
7.0 V
Logic Input Voltage Range,
V
IN
..........................
-0.3 V to V
CC
+ 0.3 V
Package Power Dissipation (TA = +25°C), P
D
A3976KLB..................................2.2
W
A3976KB ....................................2.9
W
Operating Temperature Range,
T
A
..............................-40°
C to +125°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.
FEATURES
n
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n
n
n
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30 V , ±500 mA Continuous Output Rating
35V Load Dump Survival
Output Short Circuit Protection
Coded Fault Diagnostic Outputs
Low Current Standby Mode
Open Load Monitor
Low Current Standby Mode
VBB Over Voltage Shutdown
Internal Thermal Shutdown Circuitry
Internal Low Parasitic Free Wheeling Diodes
Crossover Current Protection
PART NUMBER
A3976KLB
A3973KB
PACKAGE
24 Lead SOIC
16 Lead DIP
R
ØJA
56°C/W
°
43°C/W
°
R
ØJT
6°C/W
°
6°C/W
°
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
