A4973

A4973 Full-Bridge PWM Motor Driver Features and Benefits ▪ ±1.5 A continuous output current ▪ 50 V output voltage rating ▪ 3 V to 5.5 V logic supply voltage ▪ Internal PWM current control ▪ Fast and slow current-decay modes ▪ Sleep (low current consumption) mode ▪ Internal transient-suppression diodes ▪ Internal thermal shutdown circuitry ▪ Crossover current and UVLO protection Description Designed for bidirectional pulse width modulated (PWM) current control of inductive loads, the A4973 is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed off-time pulse duration is set by a user- selected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover current protection. Special power-up sequencing is not required. With the ENABLE input held low, the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The MODE input determines whether the PWM current-control circuitry operates in a slow current-decay mode (only the selected source driver switching) or in a fast current-decay mode (selected source and sink switching). A user-selectable blanking window prevents false triggering of the PWM current-control circuitry. With the ENABLE input held high, all output drivers are disabled. A sleep mode is provided to reduce power consumption. Continued on the next page… Packages: Package B, 16-pin DIP with exposed tabs Not to scale Package LB, 16-pin SOIC with internally fused pins Functional Block Diagram LOAD SUPPLY LOGIC SUPPLY 6 V CC SLEEP & STANDBY MODES 9 10 15 MODE 14 V BB PHASE 7 UVLO & TSD ENABLE 8 BRAKE 1 INPUT LOGIC Q BLANKING S GROUND 4 5 V CC RC 3 +– 2 RT CT V TH 4973DS – R + PWM LATCH LOAD SUPPLY 16 OUT A OUT B 11 2 SENSE RS 12 REF 13 GROUND A4973 Description (continued) When a logic low is applied to the BRAKE input, the braking function is enabled. This overrides ENABLE and PHASE to turn off both source drivers and turn on both sink drivers. The brake function can be used to dynamically brake brush DC motors. The A4973 is supplied in a choice of two power packages; a Selection Guide Part Number A4973SB-T A4973SLBTR-T Package 16-pin DIP with exposed thermal tabs 16-pin SOICW with internally-fused pins Full-Bridge PWM Motor Driver 16-pin dual-in-line plastic package with copper heat-sink tabs, and a 16-pin plastic SOIC with copper heat-sink tabs. For both package styles, the power tab is at ground potential and needs no electrical isolation. Each package type is available in a lead (Pb) free version (100% matte tin plated leadframe). Packing 25 pieces per tube 1000 pieces per reel Absolute Maximum Ratings Characteristic Load Supply Voltage Logic Supply Voltage Logic/Reference Input Voltage Range Sense Voltage Output Current, Continuous Package Power Dissipation Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VBB VCC VIN VSENSE IOUT PD TA TJ(max) Tstg Range S Fault conditions that produce excessive junction temperature will activate the device’s thermal shutdown circuitry. These conditions can be tolerated but should be avoided. 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. Notes Rating 50 6 –0.3 to 6 0.5 ±1.5 See graph –20 to 85 150 –55 to 150 Units V V V V A W ºC ºC ºC Thermal Characteristics Characteristic Package Thermal Resistance, Junction to Ambient Package Thermal Resistance, Junction to Tab Symbol RθJA Test Conditions* 2 B Package, single-layer PCB, 1 in. 2-oz. exposed copper Value 43 67 6 Units ºC/W ºC/W ºC/W LB Package, 2-layer PCB, 0.3 side 2 in. 2-oz. exposed copper each RθJT *Additional thermal information available on Allegro website. ALLOWABLE PACKAGE POWER DISSIPATION (W) 4 R θJT = 6.0°C/W BRAKE 1 2 3 4 VBB 16 15 14 13 LOAD SUPPLY OUTB MODE GROUND GROUND SENSE OUTA LOAD SUPPLY Note the A4973SB (DIP) and the A4973SLB (SOIC) are electrically identical and share a common terminal number assignment. REF RC GROUND GROUND LOGIC SUPPLY PHASE ENABLE 3 SUFFIX 'B', R θJA = 43°C/W 2 LOGIC 5 6 7 8 VBB VCC 12 11 10 9 1 SUFFIX 'LB', R θJA = 67°C/W 0 25 50 75 100 TEMPERATURE IN °C 125 150 Dwg. PP-056 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A4973 Full-Bridge PWM Motor Driver ELECTRICAL CHARACTERISTICS at TJ = 25°C, VCC = 3.0 V to 5.5 V (unless otherwise noted.) Characteristic Power Outputs Load Supply Voltage Range Output Leakage Current Output On Resistance AC Timing PWM RC Fixed Off-time PWM Minimum On Time Crossover Dead Time Maximum PWM Frequency Control Circuitry Thermal Shutdown Temperature Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis Logic Supply Current Motor Supply Current (No Load) Logic Supply Voltage Range Logic Input Voltage VIN(0) Logic Input Current Reference Input Current Comparator Input Offset Volt. Reference Input Voltage Range Gain IIN(1) IIN(0) IREF VIO VREF VIN = VCC = 5 V VIN = 0 V, VCC = 5 V VREF = 0 V to 1 V VREF = 0 V REF Pin VREF = 1 V ICC(ON) ICC(Sleep) IBB(ON) IBB(Sleep) VCC VIN(1) VENABLE = VIN(0) , VBRAKE = VIN(1) VENABLE = VMODE = VBRAKE = VIN(1) VENABLE = VIN(0) VENABLE = VMODE = VBRAKE = VIN(1) Operating TJ ∆TJ – – 2.5 0.12 – – – – 3.0 VCC × 0.55 – — — – – 0 1.9 165 15 2.75 0.17 2.7 250 500 8 V, TJ = 25°C 5 – – – –