3968_03 Datasheet, PDF (1/10 Pages) Allegro MicroSystems – DUAL FULL-BRIDGE PWM MOTOR DRIVER WITH BRAKE

3968
DUAL FULL-BRIDGE PWM MOTOR DRIVER WITH BRAKE
A3968SLB (SOIC)
OUT_1A 1
INPUT_1A 2
INPUT_{1B 3}
GROUND 4
V_BB
LOGIC LOGIC
16 OUT_2A
15 INPUT2A
14 INPUT2B
13 GROUND
SENSE ₁ 5
OUT_1B 6
LOAD
V_BB
SUPPLY ⁷
REFERENCE 8 V_REF
12 SENSE ₂
11 OUT _2B
V _CC
10
LOGIC
SUPPLY
RC 9 RC
Dwg. PP-066
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V_BB ................... 30 V
Output Current, I_OUT (peak) .......... ±750 mA
(continuous) .............................. ±650 mA
Logic Supply Voltage, V_CC ................. 7.0 V
Input Voltage, V_in ..... -0.3 V to V_CC + 0.3 V
Sense Voltage, V_S ................................ 1.0 V
Package Power Dissipation (T_A = 25°C), P_D
A3968SA ..................................... 1.8 W*
A3968SLB ................................... 1.4 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, Thermal Test
Board Standardization for Measuring Junction-
to-Ambient Thermal Resistance of Semiconductor
Packages.
The A3968SA and A3968SLB are designed to bidirectionally control two
dc motors. Each device includes two H-bridges capable of continuous output
currents of ±650 mA and operating voltages to 30 V. Motor winding current
can be controlled by the internal fixed-frequency, pulse-width modulated
(PWM), current-control circuitry. The peak load current limit is set by the
user’s selection of a reference voltage and current-sensing resistors. Except
for package style and pinout, the two devices are identical.
The fixed-frequency pulse duration is set by a user-selected external RC
timing network. The capacitor in the RC timing network also determines a
user-selectable blanking window that prevents false triggering of the PWM
current-control circuitry during switching transitions.
To reduce on-chip power dissipation, the H-bridge power outputs have
been optimized for low saturation voltages. The sink drivers feature the
Allegro^® patented Satlington^® output structure. The Satlington outputs
combine the low voltage drop of a saturated transistor and the high peak
current capability of a Darlington.
For each bridge, the INPUT_A and INPUT_B terminals determine the load
current polarity by enabling the appropriate source and sink driver pair. When
a logic low is applied to both INPUTs of a bridge, the braking function is
enabled. In brake mode, both source drivers are turned OFF and both sink
drivers are turned ON, thereby dynamically braking the motor. When a logic
high is applied to both INPUTs of a bridge, all output drivers are disabled.
Special power-up sequencing is not required. Internal circuit protection
includes thermal shutdown with hysteresis, ground-clamp and flyback diodes,
and crossover-current protection.
The A3968SA is supplied in a 16-pin dual in-line plastic package. The
A3968SLB is supplied in a 16-pin plastic SOIC with copper heat sink tabs.
The power tab is at ground potential and needs no electrical isolation. The LB
package is available in a lead (Pb) free version (100% matte tin leadframe).
FEATURES
■ ±650 mA Continuous Output Current
■ 30 V Output Voltage Rating
■ Internal Fixed-Frequency PWM Current Control
■ Satlington Sink Drivers
■ Brake Mode
■ User-Selectable Blanking Window
■ Internal Ground-Clamp & Flyback Diodes
■ Internal Thermal-Shutdown Circuitry
■ Crossover-Current Protection and UVLO Protection
Part Number
Pb-free*
R_θJA
(°C/W)
R_θJT
(°C/W)
Package
Packing
A3968SLB-T
Yes
90
A3968SLBTR-T Yes
90
6 16-Lead SOIC 47 per tube
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 fo LAST TIME BUY orders: April 27, 2007.
These variants include: A3968SA, A3968SLB, and A3968SLBTR.