3958
A3958SLB
CP
CP2
CP1
PHASE
OSC
GROUND
GROUND
LOGIC SUPPLY
ENABLE
DATA
CLOCK
STROBE
CHARGE PUMP
DMOS FULL-BRIDGE PWM
MOTOR DRIVER
Designed for pulse-width modulated (PWM) current control of dc
motors, the A3958SB and A3958SLB are capable of continuous output
currents to
±2
A and operating voltages to 50 V. Internal fixed off-
time PWM current-control timing circuitry can be programmed via a
serial interface to operate in slow, fast, and mixed current-decay
modes.
PHASE and ENABLE input terminals are provided for use in
controlling the speed and direction of a dc motor with externally
applied PWM-control signals. The ENABLE input can be
programmed via the serial port to PWM the bridge in fast or slow
current decay. Internal synchronous rectification control circuitry is
provided to reduce power dissipation during PWM operation.
Internal circuit protection includes thermal shutdown with
hysteresis, and crossover-current protection. Special power-up
sequencing is not required.
The A3958SB/SLB is supplied in a choice of two power
packages, a 24-pin plastic DIP with a copper batwing tab (package
suffix ‘B’), and a 24-lead plastic SOIC with a copper batwing tab
(package suffix ‘LB’). In both cases, the power tab is at ground
potential and needs no electrical isolation.
Data Sheet
29319.31
1
2
3
4
5
θ
24
23
NC
22
21
V
BB
20
19
18
V
REG
RANGE
NO
CONNECTION
OUT
B
LOAD SUPPLY
GROUND
GROUND
SENSE
OUT
A
NO
CONNECTION
MODE
REF
6
7
8
9
9
V
CC
LOGIC
17
16
SERIAL PORT
10
11
12
NC
15
14
÷
13
Dwg. PP-069
Note that the A3958SLB(SOIC) and A3958SB
(DIP) do not share a common terminal
assignment.
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V
BB
..................
50 V
Output Current, I
OUT
........................
±
2.0 A
Logic Supply Voltage, V
DD
................
7.0 V
Input Voltage, V
IN
....
-0.3 V to V
DD
+ 0.3 V
Sense Voltage, V
S
............................
0.5 V
Reference Voltage, V
REF
..................
2.7 V
Package Power Dissipation (T
A
= 25°C), P
D
A3958SB .................................
3.1 W*
A3958SLB ...............................
2.2 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.
* Per SEMI G42-88 Specification.
FEATURES
I
I
I
I
I
I
I
±2
A, 50 V Continuous Output Rating
Low
r
DS(on)
Outputs (270 mΩ, Typical)
Programmable Mixed, Fast, and Slow Current-Decay Modes
Serial Interface Controls Chip Functions
Synchronous Rectification for Low Power Dissipation
Internal UVLO and Thermal-Shutdown Circuitry
Crossover-Current Protection
Always order by complete part number:
Part Number
A3958SB
A3958SLB
Package
24-pin batwing DIP
24-lead batwing SOIC
R
θJA
40°C/W
56°C/W
R
θJT
6°C/W
6°C/W
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
