A4983 DMOS Microstepping Driver with Translator Features and Benefits Description Low R outputs The A4983 is a complete microstepping motor driver with DS(ON) Automatic current decay mode detection/selection built-in translator for easy operation. It is designed to operate Mixed and Slow current decay modes bipolar stepper motors in full-, half-, quarter-, eighth-, and Synchronous rectification for low power dissipation sixteenth-step modes, with an output drive capacity of up to Internal UVLO 35 V and 2 A. The A4983 includes a fixed off-time current Crossover-current protection regulator which has the ability to operate in Slow or Mixed 3.3 and 5 V compatible logic supply decay modes. Very thin profile QFN package The translator is the key to the easy implementation of the Thermal shutdown circuitry A4983. Simply inputting one pulse on the STEP input drives the motor one microstep. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The A4983 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened. The chopping control in the A4983 automatically selects the Package: 28-pin QFN (suffix ET) current decay mode (Slow or Mixed). When a signal occurs at the STEP input pin, the A4983 determines if that step results in a higher or lower current in each of the motor phases. If the change is to a higher current, then the decay mode is set to Slow decay. If the change is to a lower current, then the current decay is set to Mixed (set initially to a fast decay for a period amounting to 31.25% of the fixed off-time, then to a Continued on the next page Approximate size Typical Application Diagram V DD 0.22 F 0.1 F 0.1 F V BB VREG VCP CP1 CP2 VBB VBB VDD OUT1A Microcontroller or MS1 OUT1B Controller Logic MS2 RS1 A4983 MS3 SLEEP STEP OUT2A DIR OUT2B RESET RS2 ENABLE REF ROSC 4983DS, Rev. 1A4983 DMOS Microstepping Driver with Translator Description (continued) slow decay for the remainder of the off-time). This current decay lockout (UVLO), and crossover-current protection. Special power- control scheme results in reduced audible motor noise, increased on sequencing is not required. step accuracy, and reduced power dissipation. The A4983 is supplied in a 5 mm 5 mm 0.90 nominal surface Internal synchronous rectification control circuitry is provided to mount QFN package with exposed thermal pad (suffix ET). The improve power dissipation during PWM operation. Internal circuit package is lead (Pb) free (suffix T), with 100% matte tin plated protection includes: thermal shutdown with hysteresis, undervoltage leadframe. Selection Guide Part Number Pb-free Package Packing A4983SETTR-T Yes 28-pin QFN with exposed thermal pad 1500 pieces per 7-in. reel Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Load Supply Voltage V 35 V BB 2 A Output Current I OUT Duty Cycle < 20% 2.5 A Logic Input Voltage V 0.3 to 7 V IN Sense Voltage V 0.5 V SENSE Reference Voltage V 4V REF Operating Ambient Temperature T Range S 20 to 85 C A Maximum Junction T (max) 150 C J Storage Temperature T 55 to 150 C stg Allegro MicroSystems, Inc. 2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com