3953
BRAKE
REF
RC
GROUND
GROUND
LOGIC
SUPPLY
PHASE
ENABLE
1
2
3
4
LOGIC
5
6
7
8
V
BB
V
CC
12
11
10
9
GROUND
SENSE
OUTA
LOAD
SUPPLY
V
BB
16
15
14
13
LOAD
SUPPLY
OUTB
MODE
GROUND
FULL-BRIDGE PWM MOTOR DRIVER
Designed for bidirectional pulse-width modulated (PWM) current control
of inductive loads, the A3953S— is capable of continuous output currents to
±1.3 A and operating voltages to 50 V. Internal fixed off-time PWM current-
control circuitry can be used to regulate the maximum load current to a desired
value. The peak load current limit is set by the user’s selection of an input
reference voltage and external sensing resistor. The fixed off-time pulse
duration is set by a user- selected external RC timing network. Internal circuit
protection includes thermal shutdown with hysteresis, transient-suppression
diodes, and crossover current protection. Special power-up sequencing is not
required.
With the ENABLE input held low, the PHASE input controls load current
polarity by selecting the appropriate source and sink driver pair. The MODE
input determines whether the PWM current-control circuitry operates in a slow
current-decay mode (only the selected source driver switching) or in a fast
current-decay mode (selected source and sink switching). A user-selectable
blanking window prevents false triggering of the PWM current-control
circuitry. With the ENABLE input held high, all output drivers are disabled.
A sleep mode is provided to reduce power consumption.
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 A3953S— 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).
Data Sheet
29319.8e
Dwg. PP-056
Note the A3953SB (DIP) and the A3953SLB
(SOIC) are electrically identical and share a
common terminal number assignment.
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V
BB
. . . . . . . . . .
50 V
Output Current, I
OUT
(Continuous) . . . . . . . . . . . . . .
±1.3 A*
Logic Supply Voltage, V
CC
. . . . . . . . .
7.0 V
Logic/Reference Input Voltage Range,
V
IN
. . . . . . . . . . .
-0.3 V to V
CC
+ 0.3 V
Sense Voltage, V
SENSE
(V
CC
= 5.0 V) . . . . . . . . . . . . . . . .
1.0 V
(V
CC
= 3.3 V) . . . . . . . . . . . . . . . .
0.4 V
Package Power Dissipation,
P
D
. . . . . . . . . . . . . . . . . . . .
See Graph
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.
† Fault conditions that produce excessive junction
temperature will activate the device’s thermal
shutdown circuitry. These conditions can be
tolerated but should be avoided.
FEATURES
■
■
■
■
■
■
■
■
Sleep (Low Current Con-
±1.3 A Continuous Output Current
sumption) Mode
50 V Output Voltage Rating
■
Internal Transient-
3 V to 5.5 V Logic Supply Voltage
Suppression Diodes
Internal PWM Current Control
■
Internal Thermal-
Saturated Sink Drivers (Below 1 A)
Shutdown Circuitry
Fast and Slow Current-Decay Modes
■
Crossover-Current and
Automotive Capable
UVLO Protection
Part Number
Pb-free*
R
θJT
R
θJA
Package
Packing
(°C/W) (°C/W)
A3953SB-T
Yes
43
6
16-Pin DIP
25 per Tube
A3953SLB-T
Yes
43
6
16-Lead SOIC 47 per Tube
A3953SLBTR-T
Yes
67
6
16-Lead SOIC 1000 per reel
*Pb-based variants are being phased out of the product line. The variants cited in this
footnote are in production but have been determined to be LAST TIME BUY. This
classification indicates that sale of this device is currently restricted to existing
customer applications. The variants should not be purchased for new design
applications because obsolescence in the near future is probable. Samples are no
longer available. Status change: October 31, 2006. Deadline for receipt of LAST TIME
BUY orders: April 27, 2007. These variants include: A3953SB, A3953SLB, and
A3953SLBTR.
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
