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Details, datasheet, quote on part number:A3966SA
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Datasheet text preview:
Data Sheet 29319.25A
3966
A3966SLB (SOIC)
OUT1A PHASE 1 ENABLE 1 GROUND SENSE1 OUT 1B LOAD SUPPLY REFERENCE 1 V 2 3 4 5 6 V 7 8 V
BB BB
DUAL FULL-BRIDGE PWM MOTOR DRIVER
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 Allegro's patented SatlingtonTM 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 powerup sequencing is not required. Internal circuit protection includes thermal shutdown with hysteresis, ground-clamp and flyback diodes, and crossovercurrent 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.
16 15 14 LOGIC LOGIC 13 12 11 VCC RC 10 9
OUT 2A PHASE 2 ENABLE 2 GROUND SENSE 2 OUT 2B LOGIC SUPPLY RC
REF
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.
FEATURES
s s s s s s s s ±650 mA Continuous Output Current 30 V Output Voltage Rating Internal Fixed-Frequency PWM Current Control SatlingtonTM Sink Drivers User-Selectable Blanking Window Internal Ground-Clamp & Flyback Diodes Internal Thermal-Shutdown Circuitry Crossover-Current Protection and UVLO Protection
Always order by complete part number:
Part Number A3966SA A3966SLB Package 16-pin DIP 16-lead batwing SOIC R J A 6 0° C / W 6 7° C / W R J C 3 8° C / W -- RJT -- 6° C / W
3966 DUAL FULL-BRIDGE PWM MOTOR DRIVER
FUNCTIONAL BLOCK DIAGRAM
OUT 1A
OUT 1B
V CC PHASE 1 V BB PHASE 2
+
LOGIC SUPPLY
OUT 2A
OUT 2B
LOAD SUPPLY
UVLO & TSD
CONTROL LOGIC1
CONTROL LOGIC2
UVLO & TSD
ENABLE 1
SOURCE ENABLE 1
ENABLE 2 CURRENT-SENSE COMPARATOR 1 SENSE 1 SENSE 2 CURRENT-SENSE COMPARATOR 2
PWM LATCH 1 R Q S
BLANKING GATE 1
+
+
BLANKING GATE 2
PWM LATCH 2 R Q S
÷4 OSC RC R1S R 2S
SOURCE ENABLE 2
GROUND
RT
CT
REFERENCE
Dwg. FP-036-6
A3966SA (DIP)
SENSE 1 OUT 1B LOAD SUPPLY REFERENCE RC LOGIC SUPPLY OUT 2B SENSE 2 1
LOGIC
TRUTH TABLE
16 15 14 ENABLE 1 PHASE 1 OUT 1A GROUND GROUND OUT 2A PHASE 2 ENABLE 2
2 3 4 5 6 7 8 V REF RC V
PHASE X H L
ENABLE H L L
OUTA Off H L
OUT B Off L H
V BB
13 12 11
X = Irrelevant
CC
LOGIC
10 9
Dwg. PP-066-2
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1998, 2003 Allegro MicroSystems, Inc.
3966 DUAL FULL-BRIDGE PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V, VS = 0 V, 56 k & 680 pF RC to Ground (unless noted otherwise)
Limits Characteristic Output Drivers
Load Supply Voltage Range Output Leakage Current V BB I CEX Operating, IOUT = ±650 mA, L = 3 mH VOUT = 30 V VOUT = 0 V Output Saturation Voltage V CE(SAT) Source Driver, IOUT = -400 mA Source Driver, IOUT = -650 mA Sink Driver, IOUT = +400 mA, VS = 0.5 V Sink Driver, IOUT = +650 mA, VS = 0.5 V Clamp Diode Forward Voltage VF IF = 400 mA IF = 650 mA Motor Supply Current (No Load) IB B ( O N ) IB B ( O F F ) VENABLE1 = VENABLE2 = 0.8 V VENABLE1 = VENABLE2 = 2.4 V V CC -- -- -- -- -- -- -- -- -- -- -- <1.0 <-1.0 1.7 1.8 0.3 0.4 1.1 1.4 3.0 <1.0 30 50 -50 2.0 2.1 0.5 1.3 1.4 1.6 5.0 200 V µA µA V V V V V V mA µA
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Control Logic
Logic Supply Voltage Range Logic Input Voltage VC C V IN(1) V IN(0) Logic Input Current II N ( 1 ) II N ( 0 ) Reference Input Volt. Range Reference Input Current Reference Divider Ratio Current-Sense Comparator Input Offset Voltage Current-Sense Comparator Input Voltage Range Sense-Current Offset VR E F IR E F VR E F / V T R I P VI O VS IS O VREF = 0 V Operating IS IOUT, 50 mA IOUT 650 mA VIN = 2.4 V VIN = 0.8 V Operating Operating 4.75 2.4 -- -- -- 0.1 -2.5 3.8 -6.0 -0.3 12 -- -- -- <1.0 <-20 0 4.0 0 -- 18 5.50 -- 0.8 20 -200 2.0 1.0 4.2 6.0 1.0 24 V V V µA µA V µA -- mV V mA
NOTES: 1. Typical Data is for design information only. 2. Negative current is defined as coming out of (sourcing) the specified device terminal.
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3966 DUAL FULL-BRIDGE PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V, VS = 0 V, 56 k & 680 pF RC to Ground (unless noted otherwise) (cont.)
Limits Characteristic Control Logic (continued)
PWM RC Frequency PWM Propagation Delay Time fo s c t PWM CT = 680 pF, RT = 56 k Comparator Trip to Source OFF Cycle Reset to Source ON Cross-Over Dead Time Propagation Delay Times tc o d t t pd 1 k Load to 25 V IOUT = ±650 mA, 50% to 90%: ENABLE ON to Source ON ENABLE OFF to Source OFF ENABLE ON to Sink ON ENABLE OFF to Sink OFF PHASE Change to Sink ON PHASE Change to Sink OFF PHASE Change to Source ON PHASE Change to Source OFF 22.9 -- -- 0.2 -- -- -- -- -- -- -- -- -- -- I n c r e a s i n g V CC -- 0.1 VENABLE 1 = VENABLE 2 = 0.8 V VENABLE 1 = VENABLE 2 = 2.4 V -- -- 25.4 1.0 0.8 1.8 100 500 200 200 2200 200 2200 200 165 15 4.1 0.6 -- -- 27.9 1.4 1.2 3.0 -- -- -- -- -- -- -- -- -- -- 4.6 -- 50 9.0 kHz µs µs µs ns ns ns ns ns ns ns ns °C °C V V mA mA
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Thermal Shutdown Temp. Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis Logic Supply Current
TJ TJ VT ( U V L O ) + VT ( U V L O ) h y s IC C ( O N ) IC C ( O F F )
NOTES: 1. Typical Data is for design information only. 2. Negative current is defined as coming out of (sourcing) the specified device terminal.
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
3966 DUAL FULL-BRIDGE PWM MOTOR DRIVER
FUNCTIONAL DESCRIPTION
Internal PWM Current Control. The A3966SA and A3966SLB dual H-bridges are designed to drive both windings of a bipolar stepper motor. Load current can be controlled in each motor winding by an internal fixedfrequency PWM control circuit. The current-control circuitry works as follows: when the outputs of the Hbridge are turned on, current increases in the motor winding. The load current is sensed by the current-control comparator via an external sense resistor (RS). Load current continues to increase until it reaches the predetermined value, set by the selection of external currentsensing resistors and reference input voltage (VREF) according to the equation: ITRIP = IOUT + ISO = VREF/(4 RS) where ISO is the sense-current error (typically 18 mA) due to the base-drive current of the sink driver transistor. At the trip point, the comparator resets the sourceenable latch, turning off the source driver of that H-bridge. The source turn off of one H-bridge is independent of the other H-bridge. Load inductance causes the current to recirculate through the sink driver and ground-clamp diode. The current decreases until the internal clock oscillator sets the source-enable latches of both H-bridges, turning on the source drivers of both bridges. Load current increases again, and the cycle is repeated. The frequency of the internal clock oscillator is set by the external timing components RTCT. The frequency can be approximately calculated as: fosc = 1/(RT CT + tblank) where tblank is defined below. The range of recommended values for RT and CT are 20 k to 100 k and 470 pF to 1000 pF respectively. Nominal values of 56 k and 680 pF result in a clock frequency of 25 kHz. Current-Sense Comparator Blanking. When the source driver is turned on, a current spike occurs due to the reverse-recovery currents of the clamp diodes and switching transients related to distributed capacitance in the load. To prevent this current spike from erroneously resetting the source enable latch, the current-control comparator output is blanked for a short period of time when the source driver is turned on. The blanking time is set by the timing component CT according to the equation: tblank = 1900 CT (µs). A nominal CT value of 680 pF will give a blanking time of 1.3 µs. The current-control comparator is also blanked when the H-bridge outputs are switched by the PHASE or ENABLE inputs. This internally generated blank time is approximately 1 µs.
V BB
V PHASE
+ I
OUT
BRIDGE ON ALL OFF
BRIDGE ON SOURCE OFF ALL OFF
0
BRIDGE ON td
I TRIP
SOURCE OFF
RTC T
INTERNAL OSCILLATOR
t blank
RS
Dwg. WM-003-2
Dwg. EP-006-16
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