Brief introduction:

A4988
is a complete microstepping motor driver with built-in translator for
easy operation. This product is available in full, half, 1/4, 1/8 and
1/16 step modes operate bipolar stepper motors, output drive capacity of
up to 35 V 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 microstep. 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 control 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, undervoltage lockout (UVLO), and crossover-current
protection. Special power sequencing.

A4988 surface mount
QFN package (ES), a size of 5 mm × 5 mm, nominal overall package height
of 0.90 mm, with an exposed pad for enhanced thermal dissipation. This
package is Pb (suffix-T), with 100% matte tin leadframe plating.
Features and Benefits

· Low RDS (On) Output
· Automatic current decay mode detection / selection
· Mix with slow current decay modes
· Synchronous rectification for low power dissipation
· Internal UVLO
· Cross-current protection
· 3.3 and 5 V compatible logic supply
· Thermal shutdown circuitry
· Ground fault protection
· Load short-circuit protection
· Optional step five modes: full, 1/2, 1/4, 1/8 and 1/16

1*A4988 Stepper Motor Driver