Full-Bridge PWM Motor Driver
A4973
2
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Description (continued)
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Units
Load Supply Voltage V
BB
50 V
Logic Supply Voltage V
CC
6V
Logic/Reference Input Voltage Range V
IN
–0.3 to 6 V
Sense Voltage V
SENSE
0.5 V
Output Current, Continuous I
OUT
Output current rating may be limited by duty cycle, ambient
temperature, and heat sinking. Under any set of conditions, do
not exceed the specifi ed current rating or a junction tempera-
ture of 150°C.
±1.5 A
Transient Output Current I
OUT
t
W
< 2 s6A
Package Power Dissipation P
D
See graph W
Operating Ambient Temperature T
A
Range S –20 to 85 ºC
Maximum Junction Temperature T
J
(max)
Fault conditions that produce excessive junction temperature
will activate the device’s thermal shutdown circuitry. These
conditions can be tolerated but should be avoided.
150 ºC
Storage Temperature T
stg
–55 to 150 ºC
Selection Guide
Part Number Package Packing
A4973SB-T 16-pin DIP with exposed thermal tabs 25 pieces per tube
A4973SLBTR-T 16-pin SOICW with internally-fused pins 1000 pieces per reel
When a logic low is applied to the BRAKE input, the braking
function is enabled. This overrides ENABLE and PHASE to turn
off both source drivers and turn on both sink drivers. The brake
function can be used to dynamically brake brush DC motors.
The A4973 is supplied in a choice of two power packages; a
16-pin dual-in-line plastic package with copper heat-sink tabs,
and a 16-pin plastic SOIC with copper heat-sink tabs. For both
package styles, the power tab is at ground potential and needs no
electrical isolation. Each package type is available in a lead (Pb)
free version (100% matte tin plated leadframe).
Thermal Characteristics
Characteristic Symbol Test Conditions* Value Units
Package Thermal Resistance, Junction
to Ambient
R
JA
B Package, single-layer PCB, 1 in.
2
2-oz. exposed copper 43 ºC/W
LB Package, 2-layer PCB, 0.3 in.
2
2-oz. exposed copper each
side
67 ºC/W
Package Thermal Resistance, Junction
to Tab
R
JT
6 ºC/W
*Additional thermal information available on Allegro website.
MODE
GROUND
GROUND
LOGIC
SUPPLY
PHASE
GROUND
GROUND
RC
SENSE
LOAD
SUPPLY
Dwg. PP-056
BRAKE
REF
LOAD
SUPPLY
V
CC
OUT
B
OUT
A
V
BB
V
BB
LOGIC
ENABLE
1
2
3
4
5
6
7
89
10
11
12
13
14
15
16
50 75 100 125 150
1
0
ALLOWABLE PACKAGE POWER DISSIPATION (W)
TEMPERATURE IN °C
4
3
2
25
R = 6.0°C/W
θJT
SUFFIX 'B', R = 43°C/W
θ
JA
SUFFIX 'LB', R = 67°C/W
θJA
Note the A4973SB (DIP) and
the A4973SLB (SOIC) are
electrically identical and share
a common terminal number
assignment.
