A4975 Full-Bridge PWM Microstepping Motor Driver FEATURES AND BENEFITS DESCRIPTION 1.5 A continuous output current The A4975 is designed to drive one winding of a bipolar 50 V output voltage rating stepper motor in a microstepping mode. The outputs are Internal PWM current control rated for continuous output currents to 1.5 A and operating 3-bit nonlinear DAC voltages to 50 V. Internal pulse width modulated (PWM) current Fast, mixed fast/slow, and slow current decay modes control combined with an internal three-bit nonlinear digital- Internal thermal shutdown circuitry to-analog converter allows the motor current to be controlled Crossover-current and UVLO protection in full-, half-, quarter-, or eighth-step (microstepping) modes. Nonlinear increments minimize the number of control lines necessary for microstepping. Microstepping provides increased step resolution, and reduces torque variations and resonance PACKAGES: problems at low speed. Internal circuitry determines whether the PWM current control circuitry operates in a slow (recirculating) current decay mode, fast (regenerative) current decay mode, or in a mixed current decay mode in which the off-time is divided into a period of fast current decay and with the remainder of the fixed off-time spent in slow current decay. The combination of user-selectable current-sensing resistor and reference voltage, digitally selected output current ratio, and slow, fast, or mixed current decay modes Package B, 16-pin DIP Package LB, 16-pin SOIC provides users with a broad, variable range of motor control. with exposed tabs with internally fused pins Not to scale Continued on the next page Functional Block Diagram 10 15 6 16 PHASE V CC 7 V BB GROUND 4 5 UVLO & TSD 12 13 BLANKING CURRENT-SENSE SENSE MIXED-DECAY GATE COMPARATOR PWM LATCH 11 COMPARATOR + R PFD 1 + Q S 5 D/A BLANKING DISABLE R S V + CC RC V TH 3 V V V CC CC CC C T R T 2 8 9 14 4975-DS, Rev. 5 January 29, 2019 MCO-0000193 LOGIC SUPPLY REF OUT D 2 A D 47 k (typ) 1 D 47 k (typ) 0 OUT B 47 k (typ) LOAD SUPPLYA4975 Full-Bridge PWM Microstepping Motor Driver DESCRIPTION (CONTINUED) Internal circuit protection includes thermal shutdown with hysteresis, For both package styles, the thermally enhanced pins are at ground an undervoltage monitor, and crossover-current protection. Special potential and need no electrical isolation. Both packages are lead power-up sequencing is not required. (Pb) free, with 100% matte tin leadframe plating. The A4975 is supplied in a choice of two power packages a 16-pin dual in-line plastic package with copper heat-sink tabs (suffix B), and a 16-lead plastic SOIC with internally fused pins (suffix LB). SELECTION GUIDE Part Number Packing Package A4975SB-T * 16-pin DIP with exposed thermal tabs 25 per tube A4975SLBTR-T 16-pin SOICW with internally fused pins 1000 per reel * A4975SB-T is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: July 2, 2018. For existing customer transition, and for new customers or new appli- cations, use A4975SLBTR-T. ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Units Load Supply Voltage V 50 V BB Logic Supply Voltage V 6 V CC Logic/Reference Input Voltage Range V 0.3 to 6 V IN Sense Voltage V 0.5 V S Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do Output Current, Continuous I 1.5 A OUT not exceed the specified current rating or a junction tempera - ture of 150C. Package Power Dissipation P See graph (p. 3) W D Operating Ambient Temperature T Range S 20 to 85 C A Fault conditions that produce excessive junction temperature Maximum Junction Temperature T (max) will activate the devices thermal shutdown circuitry. These 150 C J conditions can be tolerated but should be avoided. Storage Temperature T 55 to 150 C stg 2 Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com