Hi,
I am currently attempting to use a A4899 to drive a small stepper motor, link below. I have the driver and motor hooked up per the picture on the Pololu website at the bottom of the product page. The DIR pin is connected to logic GND. Vmot is 12V from a power supply, logic voltage is 5V. I have reset and sleep shorted together. I am driving the STEP pin with a square wave from a waveform generator at the moment. I am not using the MS inputs.
The issue I am having: While driving the STEP pin with a square wave, 0-4.5V, the motor works pretty well. However at any frequency above 1kHz the motor wont spin, current drops to close to zero. It sort of just buzzes. Any ideas?
I am missing the cap b/t Vmot and GND. I didn’t have the correct value on hand. Could this be affecting anything?
Thank you for your help!