A3966

3966 ALLEGRO

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Data Sheet29319.25A† 3966 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-fre- quency, 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 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. A3966SLB OUT1B GROUND Dwg. PP-066-1 GROUND OUT1A PHASE 1 OUT2A SENSE1 ENABLE1 LOAD SUPPLY REFERENCE PHASE 2 ENABLE 2 SENSE 2 OUT 2B LOGIC SUPPLY RC LOGICLOGIC 3 14 71 0 89 RC VREF VBB VCC VBB

FEATURES

I ±650 mA Continuous Output Current I 30 V Output Voltage Rating I Internal Fixed-Frequency PWM Current Control I Satlington™ Sink Drivers I User-Selectable Blanking Window I Internal Ground-Clamp & Flyback Diodes I Internal Thermal-Shutdown Circuitry I Crossover-Current Protection and UVLO Protection Always order by complete part number: Part Number Package R θJA RθJC RθJT A3966SA 16-pin DIP 60 °C/W 38 °C/W — A3966SLB 16-lead batwing SOIC 67 °C/W — 6 °C/W ABSOLUTE MAXIMUM RATINGS Package Power Dissipation (TA = 25°C), PD Operating Temperature Range, Junction Temperature, Storage Temperature Range, 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 .

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-50002 Copyright © 1998, 2000 Allegro MicroSystems, Inc. FUNCTIONAL BLOCK DIAGRAM 8 9 OUT GROUND Dwg. PP-066-2 OUT1A PHASE 1 OUT2A SENSE 1 ENABLE1 LOAD SUPPLY REFERENCE PHASE 2 ENABLE2SENSE 2 OUT 2B LOGIC SUPPLY RC RC VREF VCC VBB GROUND LOGICLOGIC A3966SA TRUTH TABLE PHASE ENABLE OUT A OUTB XH O f fO f f HL H L LL L H X = Irrelevant R2S R1S REFERENCE VCC LOGIC SUPPLY PHASE 1 LOAD SUPPLY OUT 1A OUT1B VBB RC RT CT Dwg. FP-036-6 SENSE UVLO & TSD BLANKING GATE Q R S PWM LATCH + CURRENT-SENSE COMPARATOR ENABLE 1 OSC PHASE2 GROUND SENSE UVLO & TSD BLANKING GATE Q R S PWM LATCH+ CURRENT-SENSE COMPARATOR ENABLE 2 CONTROL LOGICSOURCE ENABLE OUT2A OUT2B 21 2 2 2 1 1 CONTROL LOGIC1 SOURCE ENABLE 1

www.allegromicro.com 3 Load Supply Voltage Range V BB Operating, IOUT = ±650 mA, L = 3 mH V CC —3 0V Output Leakage Current I CEX VOUT = 30 V — <1.0 50 µA VOUT = 0 V — <-1.0 -50 µA Output Saturation Voltage V CE(SAT) Source Driver, IOUT = -400 mA — 1.72.0 V Source Driver, IOUT = -650 mA — 1.8 2.1 V Sink Driver, IOUT = +400 mA, VS = 0.5 V — 0.3 0.5 V Sink Driver, IOUT = +650 mA, VS = 0.5 V — 0.4 1.3 V Clamp Diode Forward Voltage V F IF = 400 mA — 1.1 1.4 V IF = 650 mA — 1.4 1.6 V Motor Supply Current I BB(ON) VENABLE1 = VENABLE2 = 0.8 V — 3.0 5.0 mA (No Load) IBB(OFF) VENABLE1 = VENABLE2 = 2.4 V — <1.0 200 µA ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V, VS = 0 V, 56 kΩ & 680 pF RC to Ground (unless noted otherwise) Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Output Drivers Logic Supply Voltage Range V CC Operating 4.75 — 5.50 V Logic Input Voltage V IN(1) 2.4 — — V VIN(0) — — 0.8 V Logic Input Current I IN(1) VIN = 2.4 V — <1.0 20 µA IIN(0) VIN = 0.8 V — <-20 -200 µA Reference Input Volt. Range V REF Operating 0.1 – 2.0 V Reference Input Current I REF -2.5 0 1.0 µA Reference Divider Ratio V REF/VTRIP 3.8 4.0 4.2 — Current-Sense Comparator V IO VREF = 0 V -6.0 0 6.0 mV Input Offset Voltage Current-Sense Comparator V S Operating -0.3 — 1.0 V Input Voltage Range Sense-Current Offset I SO IS – IOUT, 50 mA ≤ IOUT ≤ 650 mA 12 18 24 mA Control Logic NOTES:1. Typical Data is for design information only. 2. Negative current is defined as coming out of (sourcing) the specified device terminal.

Worcester, Massachusetts 01615-0036 (508) 853-50004 PWM RC Frequency f osc CT = 680 pF, RT = 56 kΩ 22.9 25.4 27.9 kHz PWM Propagation Delay Time t PWM Comparator Trip to Source OFF — 1.0 1.4 µs Cycle Reset to Source ON — 0.8 1.2 µs Cross-Over Dead Time t codt 1 kΩ Load to 25 V 0.2 1.8 3.0 µs Propagation Delay Times t pd IOUT = ±650 mA, 50% to 90%: ENABLE ON to Source ON — 100 — ns ENABLE OFF to Source OFF — 500 — ns ENABLE ON to Sink ON — 200 — ns ENABLE OFF to Sink OFF — 200 — ns PHASE Change to Sink ON — 2200 — ns PHASE Change to Sink OFF — 200 — ns PHASE Change to Source ON — 2200 — ns PHASE Change to Source OFF — 200 — ns Thermal Shutdown Temp. T J — 165 — °C Thermal Shutdown Hysteresis ∆TJ —1 5— °C UVLO Enable Threshold V T(UVLO)+ Increasing VCC — 4.1 4.6 V UVLO Hysteresis V T(UVLO)hys 0.1 0.6 — V Logic Supply Current I CC(ON) VENABLE 1 = VENABLE 2 = 0.8 V — — 50 mA ICC(OFF) VENABLE 1 = VENABLE 2 = 2.4 V — — 9.0 mA Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V, VS = 0 V, 56 kΩ & 680 pF RC to Ground (unless noted otherwise) (cont.) Control Logic (continued) NOTES:1. Typical Data is for design information only. 2. Negative current is defined as coming out of (sourcing) the specified device terminal.

www.allegromicro.com 5 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 fixed- frequency PWM control circuit. The current-control circuitry works as follows: when the outputs of the H- bridge are turned on, current increases in the motor wind- ing. The load current is sensed by the current-control comparator via an external sense resistor (R S). Load current continues to increase until it reaches the predeter- mined value, set by the selection of external current- sensing resistors and reference input voltage (V REF) 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 source- enable 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. FUNCTIONAL DESCRIPTION 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 kΩ to 100 kΩ and 470 pF to 1000 pF respectively. Nominal values of 56 kΩ 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 C T according to the equa- tion: 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. Dwg. WM-003-2 VPHASE IOUT td I TRIP tblank INTERNAL OSCILLATOR BRIDGE ON SOURCE OFF BRIDGE ON R CT T ALL OFF Dwg. EP-006-16 RS BBV BRIDGE ON SOURCE OFF ALL OFF

Worcester, Massachusetts 01615-0036 (508) 853-50006 Load Current Regulation. Due to internal logic and switching delays (td), the actual load current peak will be slightly higher than the ITRIP value. These delays, plus the blanking time, limit the minimum value the current control circuitry can regulate. To produce zero current in a winding, the ENABLE terminal should be held high, turning off all output drivers for that H-bridge. Logic Inputs. A logic high on the PHASE input results in current flowing from OUT A to OUTB of that H-bridge. A logic low on the PHASE input results in current flowing from OUT B to OUTA. An internally generated dead time (tcodt) of approximately 1 µs prevents cross-over current spikes that can occur when switching the PHASE input. A logic high on the ENABLE input turns off all four output drivers of that H-bridge. This results in a fast current decay through the internal ground clamp and flyback diodes. A logic low on the ENABLE input turns on the selected source and sink driver of that H-bridge. The ENABLE inputs can be pulse-width modulated for applications that require a fast current-decay PWM. If external current-sensing circuitry is used, the internal current-control logic can be disabled by connecting the R TCT terminal to ground. The REFERENCE input voltage is typically set with a resistor divider from VCC. This reference voltage is internally divided down by 4 to set up the current-com- parator trip-voltage threshold. The reference input voltage range is 0 to 2 V. Output Drivers. To minimize on-chip power dissipation, the sink drivers incorporate a Satlington™ structure. The Satlington output combines the low V CE(sat) features of a saturated transistor and the high peak-current capability of a Darlington (connected) transistor. A graph showing typical output saturation voltages as a function of output current is on the next page. Miscellaneous Information. Thermal protection circuitry turns off all output drivers should the junction temperature reach +165 °C (typical). This is intended only to protect the device from failures due to excessive junction temperatures and should not imply that output short circuits are permitted. Normal operation is resumed when the junction temperature has decreased about 15 °C. The A3966 current control employs a fixed-fre- quency, variable duty cycle PWM technique. As a result, the current-control regulation may become unstable if the duty cycle exceeds 50%. To minimize current-sensing inaccuracies caused by ground trace I R drops, each current-sensing resistor should have a separate return to the ground terminal of the device. For low-value sense resistors, the I•R drops in the printed-wiring board can be significant and should be taken into account. The use of sockets should be avoided as their contact resistance can cause variations in the effective value of R The LOAD SUPPLY terminal, VBB, should be decoupled with an electrolytic capacitor (47 µF recom- mended) placed as close to the device as physically practical. To minimize the effect of system ground IR drops on the logic and reference input signals, the system ground should have a low-resistance return to the load supply voltage. The frequency of the clock oscillator will determine the amount of ripple current. A lower frequency will result in higher current ripple, but reduced heating in the motor and driver IC due to a corresponding decrease in hysteretic core losses and switching losses respectively. A higher frequency will reduce ripple current, but will increase switching losses and EMI. FUNCTIONAL DESCRIPTION (continued)

www.allegromicro.com 7 Dwg. EP-047-4A PHASE 2 ENABLE2 47 µF +24 V 56 kΩ 680 pF PHASE1 ENABLE1 +5 V 39 kΩ10 kΩ 0.5 Ω +5 V 0.5 Ω LOGICLOGIC 3 14 71 0 89 RC VREF VBB VCC VBB TYPICAL APPLICATION 200 Dwg. GP-064-1 400 700300 OUTPUT CURRENT IN MILLIAMPERES 2.0 OUTPUT SATURATION VOLTAGE IN VOLTS 1.0 0.5 1.5 2.5 500 600 TA = +25°C SOURCE DRIVER SINK DRIVER Typical output saturation voltages showing Satlington™ sink-driver operation. The products described here are manufactured under one or more Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro products are not authorized for use as critical components in life-support devices or systems without express written approval. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsi- bility for its use; nor for any infringement of patents or other rights of third parties which may result from its use.

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Worcester, Massachusetts 01615-0036 (508) 853-500010 A3966SA Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) NOTES: 1. Exact body and lead configuration at vendor ’s option within limits shown. 2. Lead spacing tolerance is non-cumulative 3. Lead thickness is measured at seating plane or below. 0.014 0.008 0.300 BSC Dwg. MA-001-16A in 0.430 MAX 1 8 0.280 0.240 0.210 MAX 0.070 0.045 0.015 MIN 0.022 0.014 0.100 BSC 0.005 MIN 0.150 0.115 0.775 0.735 0.355 0.204 7.62 BSC Dwg. MA-001-16A mm 10.92 MAX 1 8 7.11 6.10 5.33 MAX 1.77 1.15 0.39 MIN 0.558 0.356 2.54 BSC 0.13 MIN 3.81 2.93 19.68 18.67

www.allegromicro.com 11 1 2 3 0.2992 0.2914 0.4133 0.3977 0.419 0.394 0.020 0.013 0.0926 0.1043 0.0040 MIN. 0.0125 0.0091 0.050 0.016 0° TO 8° Dwg. MA-008-16A in 0.050 BSC 16 9 A3966SLB Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) NOTES: 1. Exact body and lead configuration at vendor ’s option within limits shown. 2. Lead spacing tolerance is non-cumulative 3. Webbed lead frame. Leads 4 and 13 are internally one piece. 916 1 2 3 7.60 7.40 10.50 10.10 10.65 10.00 0.51 0.33 2.65 2.35 0.10 MIN. 0.32 0.23 1.27 0.40 0° TO 8° Dwg. MA-008-16A mm 1.27 BSC

Worcester, Massachusetts 01615-0036 (508) 853-500012 MOTOR DRIVERS Function Output Ratings* Part Number † INTEGRATED CIRCUITS FOR BRUSHLESS DC MOTORS 3-Phase Power MOSFET Controller — 28 V 3933 3-Phase Power MOSFET Controller — 50 V 3932 3-Phase Power MOSFET Controller — 50 V 7600 2-Phase Hall-Effect Sensor/Driver 400 mA 26 V 3626 Bidirectional 3-Phase Back-EMF Controller/Driver ±600 mA 14 V 8906 2-Phase Hall-Effect Sensor/Driver 900 mA 14 V 3625 3-Phase Back-EMF Controller/Driver ±900 mA 14 V 8902–A 3-Phase Controller/Drivers ±2.0 A 45 V 2936 & 2936-120 INTEGRATED BRIDGE DRIVERS FOR DC AND BIPOLAR STEPPER MOTORS Dual Full Bridge with Protection & Diagnostics ±500 mA 30 V 3976 PWM Current-Controlled Dual Full Bridge ±650 mA 30 V 3966 PWM Current-Controlled Dual Full Bridge ±650 mA 30 V 3968 PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 2916 PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 2919 PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 6219 PWM Current-Controlled Dual Full Bridge ±800 mA 33 V 3964 PWM Current-Controlled Full Bridge ±1.3 A 50 V 3953 PWM Current-Controlled Dual Full Bridge ±1.5 A 45 V 2917 PWM Current-Controlled Dual Full Bridge ±1.5 A 45 V 2918 PWM Current-Controlled Microstepping Full Bridge ±1.5 A 50 V 3955 PWM Current-Controlled Microstepping Full Bridge ±1.5 A 50 V 3957 PWM Current-Controlled Dual DMOS Full Bridge ±1.5 A 50 V 3972 Dual Full-Bridge Driver ±2.0 A 50 V 2998 PWM Current-Controlled Full Bridge ±2.0 A 50 V 3952 DMOS Full Bridge PWM Driver ±2.0 A 50 V 3958 Dual DMOS Full Bridge ±2.5 A 50 V 3971 UNIPOLAR STEPPER MOTOR & OTHER DRIVERS Voice-Coil Motor Driver ±500 mA 6 V 8932–A Voice-Coil Motor Driver ±800 mA 16 V 8958 Unipolar Stepper-Motor Quad Drivers 1 A 46 V 7024 & 7029 Unipolar Microstepper-Motor Quad Driver 1.2 A 46 V 7042 Unipolar Stepper-Motor Translator/Driver 1.25 A 50 V 5804 Unipolar Stepper-Motor Quad Driver 1.8 A 50 V 2540 Unipolar Stepper-Motor Quad Driver 1.8 A 50 V 2544 Unipolar Stepper-Motor Quad Driver 3 A 46 V 7026 Unipolar Microstepper-Motor Quad Driver 3 A 46 V 7044 * Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits or over-current protection voltage limits. Negative current is defined as coming out of (sourcing) the output. † Complete part number includes additional characters to indicate operating temperature range and package style. Also, see 3175, 3177, 3235, and 3275 Hall-effect sensors for use with brushless dc motors.