A4988 is a micro-stepping motor driver with built-in translator for easy operation. A4988 module supports full, half, 1/4, 1/8 and 1/16 step modes, output drive capacity of up to 35V and ± 2 A. A4988 includes a fixed off-time current regulator, the regulator in slow or mixed decay modes. A4988 converter is the key to the easy implementation. As long as the "step" input inputting one pulse drives the motor one micro step. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. A4988 interface is very suitable for complex microprocessor is unavailable or is overburdened.
In the micro-step operation, A4988 chopping controls inside automatically selects the current decay mode (Slow or Mixed). In mixed decay mode, the device is initially set to a fixed downtime in some fast decay, then the rest of the slow decay downtime. Mixed decay current control scheme results in reduced audible motor noise, increased step accuracy, and reduced power consumption. Internal synchronous rectification control circuitry is provided to improve the pulse-width modulation (PWM) operation power consumption. Internal circuit protection includes: thermal shutdown with hysteresis, under voltage lockout (UVLO), and crossover-current protection.