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A4988 Datasheet Allegro MicroSystems Download

A4988 Datasheet 

A4988 Datasheet Allegro MicroSystems Download - The A4988 is a complete microstepping motor driver with built-in translator for easy operation. It is designed to operate bipolar stepper motors in full-, half-, quarter-, eighth-, and sixteenth-step modes, with an output drive capacity of up to  35 V and ±2 A. 

The A4988 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 A4988. 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.

A4988 Datasheet Allegro MicroSystems Download
A4988 Datasheet


The A4988 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened. During stepping operation, the chopping control in the A4988 automatically selects the current decay mode: slow or mixed. 

In mixed decay mode, the device is set initially to a fast decay for a proportion of the fixed off-time, then to a slow decay for the remainder of the off-time. Mixed decay current control results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.


A4988 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
  • Crossover-current protection
  • 3.3 and 5 V compatible logic supply
  • Thermal shutdown circuitry
  • Short-to-ground protection
  • Shorted load protection
  • Five selectable step modes: full, 1 / 2 , 1 / 4 , 1 / 8 , and 1 / 16

Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes: thermal shutdown with hysteresis, undervoltage lockout (UVLO), and crossover-current protection. Special power-on sequencing is not required.

The A4988 is supplied in a surface-mount QFN package (ET), 5 mm × 5 mm, with a nominal overall package height of 0.90 mm and an exposed pad for enhanced thermal dissipation. It is lead (Pb) free (suffix –T), with 100% matte-tin-plated leadframes.



Copyright 2020, Allegro MicroSystems. Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current.