A4988 driver :

The A4988 driver Stepper Motor Driver is a complete micro-stepping motor driver with built-in converter, easy to operate. It operates from 8 V to 35 V and can deliver up to approximately 1 A per phase without a heat sink or forced air flow (it is rated for 2 A per coil with sufficient additional cooling).

A4988 driver Stepper Motor Driver includes a fixed off-time current regulator, the regulator can be in slow or mixed decay mode. The converter is the key to the easy implementation of the A4988.

Provide internal synchronous rectification control circuitry, in order to improve the pulse width modulation (PWM) power consumption during operation.

• 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.
• Interface is very suitable for complex microprocessor is unavailable or is overburdened.
• In the micro-step operation, its 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, under-voltage lockout (UVLO), and crossover-current protection. Special power sequencing.
• Its 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 lead-frame plating.

A4988 driver Features:

• 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 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
• Simple step and direction control interface
• Five different step resolutions: full-step, half-step, quarter-step, eighth-step, and sixteenth-step
• Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates
• Intelligent chopping control that automatically selects the correct current decay mode (fast decay or slow decay)
• Over-temperature thermal shutdown, under-voltage lockout, and crossover-current protection
• Short-to-ground and shorted-load protection