3964

3964 DUAL FULL-BRIDGE PWM MOTOR DRIVER 3964 Designed for pulse-width modulated (PWM) current control of bipolar stepper motors, the A3964SB and A3964SLB are capable of continuous output currents to ±800 mA and operating voltages to 30 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. An internal precision voltage reference is provided to improve motor peak-current control accuracy. The peak load current limit is set by the user’s selection of an external resistor divider and current-sensing resistors. The fixed off-time pulse duration is set by user-selected external RC timing networks. 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. This eliminates the need for two external RC filter networks on the current-sensing comparator inputs. For each bridge the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. For each bridge the ENABLE input, when held high, disables the output drivers. Special power-up sequencing is not required. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. The A3964SB is supplied in a 24-pin plastic DIP with copper heat sink tabs; A3964SLB is supplied in a 20-lead plastic SOIC with copper heat sink tabs. The power tabs are at ground potential and need no electrical isolation. Data Sheet 29319.28* DUAL FULL-BRIDGE PWM MOTOR DRIVER A3964SLB OUT 1B SENSE 1 OUT 1A LOAD SUPPLY GROUND GROUND V REF(IN) RC 1 PHASE 1 ENABLE 1 1 2 3 4 5 6 7 9 8 VBB V CC 1 2 20 19 18 17 16 15 14 OUT 2B SENSE 2 OUT 2A LOGIC SUPPLY GROUND GROUND V REF(OUT) RC 2 PHASE 2 ENABLE 2 PWM 2 13 θ2 12 11 9 10 θ1 PWM 1 Dwg. PP-047-1 ABSOLUTE MAXIMUM RATINGS Load Supply Voltage, VBB . . . . . . . . . 33 V Output Current, IOUT (10 µ s) . . . . . . ±1.0 A* (continuous) . . . . . . . . . . . . . ±800 mA* Logic Supply Voltage, VCC . . . . . . . . . 7.0 V Logic Input Voltage Range, VIN . . . . . . . . . . . -0.3 V to VCC + 0.3 V Sense Voltage, VS . . . . . . . . . . . . . . . 1.0 V Reference Output Current, IREF(OUT) . . . . . . . . . . . . . . . . . . 1.0 mA Package Power Dissipation, PD . . . . . . . . . . . . . . . . . . . . See Graph 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. † 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 s s s s s s s ±800 mA Continuous Output Current Rating 30 V Output Voltage Rating Internal PWM Current Control, Saturated Sink Drivers Internally Generated, Precision 2.5 V Reference Internal Transient-Suppression Diodes Internal Thermal-Shutdown Circuitry Crossover-Current Protection, UVLO Protection Always order by complete part number: Part Number A3964SB A3964SLB Package 24-Pin DIP 20-Lead Wide-Body SOIC 3964 DUAL FULL-BRIDGE PWM MOTOR DRIVER A3964SB ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS 5 RθJT = 6.0°C/W NO CONNECT. OUT 1B SENSE 1 1 2 3 4 5 6 7 8 9 9 NC NC 24 23 NO CONNECT. OUT 2B SENSE 2 OUT 2A LOGIC SUPPLY GROUND GROUND V REF(OUT) RC 2 PHASE 2 ENABLE 2 NO CONNECT. 4 1 2 22 21 3 SUFFIX 'B', R θJA = 40°C/W OUT 1A LOAD SUPPLY GROUND GROUND VBB V CC 20 19 18 17 2 1 SUFFIX 'LB', R θJA = 60°C/W V REF(IN) RC 1 PWM 2 16 θ2 15 14 0 25 50 75 100 TEMPERATURE IN °C 125 150 Dwg. GP-049-4 PHASE 1 ENABLE 1 NO CONNECT. 10 11 12 θ1 PWM 1 NC NC 13 Dwg. PP-005-2 FUNCTIONAL BLOCK DIAGRAM (A3964SLB pinning shown) LOGIC SUPPLY OUT 1B LOAD SUPPLY OUT 2A OUT 1A OUT 2B 17 VCC 3 1 4 18 20 UVLO & TSD VBB PWM 1 1 2 ENABLE1 10 PWM 2 PHASE 1 9 12 PHASE 2 11 ENABLE2 SOURCE DISABLE – + 2.5 V REFERENCE V REF(IN) – + SOURCE DISABLE ONE SHOT ONE SHOT REF OUT SENSE 1 SENSE 2 RC1 RT CT RA RS RB RS RC2 8 2 14 REF IN 7 5 6 15 16 19 13 CT RT Dwg. FP-033-1 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1997 Allegro MicroSystems, Inc. 3964 DUAL FULL-BRIDGE PWM MOTOR DRIVER TRUTH TABLE ENABLE H L L PHASE X H L OUTA Off H L OUTB Off L H X = Irrelevant ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.25 V, VS = 0 V, 30 kΩ & 1000 pF RC to Ground (unless noted otherwise) Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Output Drivers Load Supply Voltage Range Output Sustaining Voltage Output Leakage Current V BB VCE(sus) ICEX Operating, IOUT = ±800 mA, L = 3 mH IOUT = ±800 mA, L = 3 mH, V BB = 33 V VOUT = VBB = 33 V VOUT = 0 V, VBB = 33 V Output Saturation Voltage VCE(SAT) Source Driver, IOUT = -500 mA Source Driver, IOUT = -750 mA Source Driver, IOUT = -800 mA Sink Driver, IOUT = +500 mA Sink Driver, IOUT = +750 mA Sink Driver, IOUT = +800 mA Clamp Diode Forward Voltage (Sink or Source) VF IF = 500 mA IF = 750 mA IF = 800 mA Motor Supply Current (No Load) IBB(ON) IBB(OFF) VENABLE = 0.8 V VENABLE = 2.4 V 5.0 33 — — — — — — — — — — — — — — —