A3976 Dual Full Bridge Protected Motor Driver Discontinued Product These parts are no longer in production The device should not be purchased for new design applications. Samples are no longer available. Date of status change: May 1, 2006 Recommended Substitutions: For new customers or new applications, refer to the 3980. NOTE: For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative. Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use. Page 1 of 6 3976 PRELIMINARY DATASHEET - 8/24/04 (Subject to change without notice) V BB 1 2 4 V CC ENABLE1 2 2 3 ENABLE2 PHASE1 3 2 2 PHASE2 NC 4 2 1 NC NC 5 2 0 NC GROUND GROUND n/c OUT1A 6 7 A3976KLB 1 9 GROUND 1 8 GROUND 8 1 7 n/c 9 1 6 OUT2A n/c 1 0 DUAL FULL BRIDGE PROTECTED MOTOR DRIVER The A3976 is designed to drive both windings of a bipolar stepper motor or bidirectionally control two DC Motors. Both H-Bridges are capable of continuous output currents of up to +/- 500 mA and operating voltages to 27V. Free wheeling, substrate isolated diodes are included for output transient suppression when switching motors or other inductive loads. For each bridge the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The ENABLE input, when held high, enables the respective output H-bridge. When both ENABLE pins are held low the device will enter SLEEP mode and consume less than 100µA. 1 5 n/c FAULT1 11 1 4 FAULT2 OUT1B 12 1 3 OUT2B ABSOLUTE MAXIMUM RATINGS at TA = +25°C Operating Supply Voltage, VBB .................... 27 V Non-Operating Supply Voltage .................... 35 V Output Current, IOUT ............................±500 mA* Logic Supply Voltage, VCC .......................... 7.0 V Fault Output Voltage ................................... 7.0 V Logic Input Voltage Range, VIN ......................... -0.3 V to VCC + 0.3 V Package Power Dissipation (TA = +25°C), PD A3976KLB.................................. 2.2 W Operating Temperature Range, TA .............................. -40°C to +125°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. The A3976 is protected to ensure safe operation in harsh operating environments and was designed specifically for automotive applications. Protection circuitry will check for open or shorted load, motor lead short to ground or supply, VBB overvoltage, VCC undervoltage, and thermal shutdown. If any of these conditions are detected the outputs will be disabled and fault information will be output to diagnostic pins FAULT1 and FAULT2. The A3976 is supplied in a 24-lead plastic SOIC with a copper batwing tab (suffix ‘LB’). FEATURES T T T T T T T T T T T ±500 mA Continuous Output Rating 35V Load Dump Survival Output Short Circuit Protection Coded Fault Diagnostic Outputs Low Current Standby Mode Open Load Monitor Low Current Standby Mode VBB Over Voltage Shutdown Internal Thermal Shutdown Circuitry Internal Low Parasitic Free Wheeling Diodes Crossover Current Protection Page 2 of 6 3976 – DUAL FULL BRIDGE PROTECTED MOTOR DRIVER Functional Block Diagram (one of two bridges shown) Input Logic PHASE X 0 1 ENABLE 0 1 1 OUTA Off Low High OUTB Off High Low Fault Logic Fault Condition Thermal Shutdown Short to Battery or Open Load Short to Ground Normal Operation FAULT1 Low Low High High FAULT2 Low High Low High Page 3 of 6 3976 – DUAL FULL BRIDGE PROTECTED MOTOR DRIVER ELECTRICAL CHARACTERISTICS at TA = -40°C to +125°C, VBB = 16V, VCC = 4.5 to 5.5 V (Unless noted otherwise) Limits Characteristics Symbol Test Conditions Min. Typ. Max. Units – 27 V 5.5 V Output Drivers Load Supply Voltage Range VBB Operating 6 Logic Supply Range VCC Operating 4.5 Output Current Limit ICL Outputs A or B = GROUND 0.7 1.1 – A Outputs A or B = VBB 0.7 1.1 – A VOUT = VBB – <1.0 50 µA VOUT = 0 V – <1.0 -50 µA Source Driver, IOUT = -350 mA – 1.0 1.2 V Source Driver, IOUT = -500 mA – 1.2 1.3 Sink Driver, IOUT = +350 mA – 0.2 0.4 V Sink Driver, IOUT = +500 mA – 0.4 0.6 V IF = 500 mA (Sink / Ground Clamp) – 1.2 1.5 V IF = 500 mA (Source / Flyback) – 1.55 2.0 V ENABLE1 = ENABLE2 = High – 7 10 mA Sleep Mode ENABLE1 = ENABLE2 = Low – – 25 µA ENABLE1 = ENABLE2 = High – 45 50 mA Sleep Mode, ENABLE1 = ENABLE2 = Low – – 75 µA VIN(1) 0.7VCC – - V VIN(0) – – .3VCC V Output Leakage Current Output Saturation Voltage Clamp Diode Forward Voltage ICEX VCE(SAT) VF (Flyback or Ground Clamp) Control Logic Motor Supply Current IBB (No Load) Logic Supply Current Logic Input Voltage Logic Input Current ICC IIN(1) VIN = 5 V – 50 100 µA IIN(0) VIN = 0 V – -1.0 -2.0 µA Page 4 of 6 3976 – DUAL FULL BRIDGE PROTECTED MOTOR DRIVER ELECTRICAL CHARACTERISTICS at TA = -40°C to +125°C, VBB = 16 V, VCC = 4.5 to 5.5 V (Unless noted otherwise) Limits Characteristics Symbol Test Conditions Min. Typ. Max. Units IF-LEAK VF = 5 V, No Faults - - 10 µA – 0.8 V Fault Circuitry Fault Output Leakage Current Fault Output Voltage VFL Fault Output Current IF Output Open Load Current Thermal Fault Temp. Thermal Fault Hysteresis Fault Condition Asserted, IF = 25 µA VF = 5 V, ENABLE = High 25 50 75 µA VBB = 12 V – 2 – mA TF – 170 – °C TFHYS – 10 – °C 27 30 33 V I OUT-O.L. OVLO Enable Threshold VBB rising OVLO Hysteresis 1.5 UVLO Enable Threshold VCC rising UVLO Hysteresis V 3.5 4 4.49 V – 400 – mV Timing Open Fault to Reset Delay trs VBB = 12 V – – 25 µs PHASE_X Delay to OPEN Fault tof VBB = 12 V – 8 – µs PHASE_X Delay to S.C. Fault tSC VBB = 12 V – 5 – µs ENABLE_X Delay to Fault tof VBB = 12 V – 5 – µs Propagation Delay Times tpd IOUT = ±0.35A, 50%TO 90% ENABLE ON TO SOURCE ON – 0.3 µs ENABLE OFF TO SOURCE OFF – 0.4 µs ENABLE ON TO SINK ON – 0.3 µs ENABLE OFF TO SINK OFF – 0.2 µs PHASE CHANGE TO SINK ON – 4.0 µs PHASE CHANGE TO SINK OFF – 0.3 µs PHASE CHANGE TO SOURCE ON – 4.0 µs PHASE CHANGE TO SOURCE OFF – 0.4 µs 0.5 3.0 Cross Over Dead Time tCODT 1KΩ (1k+1k) Load (VBB to OUT to GND) 6.0 µs Page 5 of 6 3976 – DUAL FULL BRIDGE PROTECTED MOTOR DRIVER APPLICATION NOTES Open Load Protection. During normal PWM operation, diagnostic circuitry will look for a minimum source current level after a bridge is signalled on. Additionally, the diode flyback is monitored on the proper output. The logic will signal a fault and disable the outputs if it determines that the current is below the minimum level AND no flyback is occurring. If the inductive load is too large, the current would take too long to reach the minimal level and a false open load would be reported. It is recommended that the inductive load be less than 38 mH. Short Circuit Protection. Internal sense resistors in series with VBB and ground will trip the fault circuitry if greater than 1.1 A is detected. To prevent false overcurrent events due to reverse recovery spikes of the clamp diodes, the current monitor is blanked for 5µs after a high side is signalled to turn on. If an additional input command follows after the initial fault, the selected pair of drivers will pulse on for the 5µs blanking duration. The short circuit fault will remember the input state where the fault occurred and will wait for that particular logic state after the short has been removed before normal operation is allowed to resume. Thermal Protection. Circuitry turns OFF all drivers when the junction temperature reaches 170°C typically. It is intended only to protect the device from failures due to excessive junction temperatures and has a hysteresis of approximately 15°C. Layout. The printed wiring board should use a heavy ground plane. For optimum electrical and thermal performance, the driver should be soldered directly onto the board. The load supply terminal, VBB, should be decoupled with an electrolytic capacitor (> 47 µF is recommended) placed as close to the device as possible. Fault Outputs. Both Fault outputs are open-collectorsink types. These turn on (go low) when there is a fault. Each requires a pull-up resistor, rated at approximately 100 kΩ at 5 V. Page 6 of 6 3976 - DUAL FULL BRIDGE PROTCTED MOTOR DRIVER Terminal List Name VBB ENABLE1 PHASE1 GROUND OUT1A FAULT1 OUT1B OUT2B FAULT2 OUT2A PHASE2 ENABLE2 VCC NC Description Motor Supply Voltage Control Logic – Bridge 1 Control Logic – Bridge 1 Power Ground Return Bridge 1 Output A Diagnostic Output Bridge 1 Output B Bridge 2 Output B Diagnostic Output Bridge 2 Output A Control Logic – Bridge 2 Control Logic – Bridge 2 Logic Supply No Connect SOIC - 24 1 2 3 18,19,6,7 9 11 12 13 14 16 22 23 24 4,5,8,15,17,20,21