A4988 is a complete microstepping motor driver with built-in translator for easy operation. The product is available in full, half , 1/4, 1 / 8 and 1 /16 step mode to operate bipolar stepper motors of an output drive capability of up to 35 V and ± 2 A. A4988 includes a fixed off-time current regulator, the regulator can operate in slow or mixed decay modes. Converter is easy to implement key for A4988. Just enter a pulse in the "step" input drives the motor to produce micro-step. Without the need for phase sequence tables, high frequency control lines, or complex interfaces to program. A4988 interface is ideal for complex microprocessor is unavailable or overloaded applications.

In the micro-step operation, the chopper control A4988 automatically selects within the current decay mode ( slow or mixed ). In mixed decay mode, the device is initially set to a fixed part of the rapid decay in downtime and slow decay for the remainder of downtime. Mixed decay current control scheme results in reduced audible motor noise, increased step accuracy, and reduced power consumption. Internal synchronous rectification control circuitry provides to improve the pulse-width modulation (PWM) operation power consumption. Internal circuit protection includes: thermal shutdown with hysteresis , undervoltage lockout (UVLO) and crossover current protection. No need special power sequencing.

A4988 uses surface mount QFN package (ES), size of 5 mm x 5 mm, containing a radiator on the surface layer, with exposed pad for enhanced thermal dissipation. This package is Pb-free ( suffix -T), with 100% matte tin leadframe plating.