A3984 Datasheet | Allegro MicroSystems

DMOS Microstepping Driver with Translator Features AND BENEFITS - Low RDS(ON) outputs - Automatic current decay mode detection/selection - Mixed and Slow current decay modes - Synchronous rectification for low power dissipation - Internal UVLO and thermal shutdown circuitry - Crossover-current protection PACKAGE: 24-pin TSSOP with exposed thermal pad (suffix LP) Not to scale DESCRIPTION The A3984 is a plete microstepping motor driver with built-in translator for easy operation. It is designed to operate bipolar stepper motors in full-, half-, quarter-, and sixteenth-step modes, with an output drive capacity of up to 35 V and ±2 A. The A3984 includes a fixed off-time current regulator which has the ability to operate in Slow or Mixed decay modes. The translator is the key to the easy implementation of the A3984. Simply inputting one pulse on the STEP input drives the motor one microstep. There are no phase sequence tables, high frequency control lines, or plex interfaces to program. The A3984 interface is an ideal fit for applications where a plex microprocessor is unavailable or is overburdened. The chopping control in the A3984 automatically selects the current decay mode (Slow or Mixed). When a signal occurs at the STEP input pin, the A3984 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 slow decay for the remainder of the Continued on the next page… Pinout Diagram CP1 1 CP2 2 VCP 3 VREG 4 MS1 5 MS2 6 RESET 7 ROSC 8 SLEEP 9 VDD 10 STEP 11 REF 12 Reg Charge Pump Translator & Control Logic 24 GND 23 ENABLE 22 OUT2B 21 VBB2 20 SENSE2 19 OUT2A 18 OUT1A 17 SENSE1 16 VBB1 15 OUT1B 14 DIR 13 GND 26184.30, Rev. 7 MCO-0000917 July 6, 2022 DMOS...