A3967 stepper motor driver - EasyDriver, 750 mA per phase, 6-30 V

Product Overview

• Driver board for bipolar stepper motors with Allegro A3967 chip
• Supports motors with 4, 6, or 8 wires; output current adjustable up to 750 mA per phase
• Full-step, half-step, quarter-step, and eighth-step operation selectable
• Control via STEP and DIR logic levels
• Motor supply 6 to 30 V; logic supplied at 3.3 or 5 V by the integrated regulator
• Supplied with solder pads without pin headers; adjust the current using the potentiometer

Product Description

This stepper motor driver controls bipolar motors with two pairs of coils, including motors with four, six, or eight wires. The A3967 chip manages the current flow through both phases, so only two simple logic signals are required: STEP for each step and DIR for the direction of rotation. The resolution can be set to full-step, half-step, quarter-step, or eighth-step using two additional inputs; the factory setting is eighth-step, which divides a motor with 200 full steps into 1600 microsteps, for example. This makes movements smoother and more precise.

The current flowing through each phase can be finely adjusted using a potentiometer on the board, which is crucial for the motor torque. The motor supply requires 6 to 30 V. For the logic signals, the integrated voltage regulator provides either 5 V or 3.3 V, depending on the logic level used by the controlling microcontroller board. The 5 V output pin can supply additional components with low current; if the APWR solder jumper is removed, this pin becomes an input instead and enables external logic power supplied from the main power circuit.

Additional inputs allow the motor to be switched off under program control. RST resets the sequence register and disables all outputs, SLP reduces standby power consumption by shutting down the output stages, and ENABLE disables all outputs without affecting the control signals. This allows the motor to be switched off as needed without rewiring. Three equivalent ground connections distribute the return path across the board.

The board is supplied with unpopulated solder pads on a standard pitch; the included pin header can be soldered on as needed. Operation requires a separate motor power supply that provides 6 to 30 V, as well as a microcontroller or signal source that provides STEP, DIR, and, if required, MS1 and MS2 levels.

Safety Information

The board is not intended for installation in the household power circuit. It is intended exclusively for building prototypes and for testing and development purposes. The motor supply and logic levels may only be supplied by separate power sources designed for these voltages; work on or near electrical installations is reserved for qualified electricians. If you are unsure about the power supply, consult a qualified electrician before commissioning the device.