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3966_03 Datasheet, PDF (1/9 Pages) Allegro MicroSystems – DUAL FULL-BRIDGE PWM MOTOR DRIVER
3966
DUAL FULL-BRIDGE PWM
MOTOR DRIVER
A3966SLB (SOIC)
OUT1A 1
PHASE 1 2
ENABLE 1 3
GROUND 4
V BB
LOGIC LOGIC
16 OUT2A
15 PHASE 2
14 ENABLE 2
13 GROUND
SENSE1 5
OUT1B 6
LOAD
SUPPLY
7
V BB
REFERENCE 8 VREF
12 SENSE 2
11 OUT 2B
VCC
10
LOGIC
SUPPLY
RC 9 RC
Dwg. PP-066-1
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, VBB ...................... 30 V
Output Current, IOUT (peak) ........... ±750 mA
(continuous) .............................. ±650 mA
Logic Supply Voltage, VCC .................... 7.0 V
Input Voltage, Vin ........ -0.3 V to VCC + 0.3 V
Sense Voltage, VS ................................ 1.0 V
Package Power Dissipation (TA = 25°C), PD
A3966SA ..................................... 2.08 W*
A3966SLB ................................... 1.87 W*
Operating Temperature Range,
TA ..................................... -20°C to +85°C
Junction Temperature,
TJ .................................................. +150°C
Storage Temperature Range,
TS ................................... -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 A3966SA and A3966SLB are designed to drive both windings of a two-
phase bipolar stepper motor. 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, a PHASE input controls load-current polarity by selecting the
appropriate source and sink driver pair. For each bridge, an ENABLE input, when
held high, disables the output drivers. 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 A3966SA is supplied in a 16-pin dual in-line plastic package. The
A3966SLB is supplied in a 16-lead plastic SOIC with copper heat sink tabs. The
power tab is at ground potential and needs no electrical isolation. The A3966SLB
is also available in a lead (Pb) free version, with 100% matte tin leadframe plating.
FEATURES
■ ±650 mA Continuous Output Current
■ 30 V Output Voltage Rating
■ Internal Fixed-Frequency PWM Current Control
■ Satlington Sink Drivers
■ User-Selectable Blanking Window
■ Internal Ground-Clamp & Flyback Diodes
■ Internal Thermal-Shutdown Circuitry
■ Crossover-Current Protection and UVLO Protection
P a rt Num b e r P b -fre e *
P ackage
P acking
A 3966S LB -T
Ye s
1 6 -L e a d S O IC 4 7 p e r tub e
A 3966S LB TR-T
Ye s
1 6 -L e a d S O IC 1 0 0 0 p e r re e l
*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: A3966SA, A3966SLB, and A3966SLBTR.