Hi,
we're using DRV8811 for a new project driving Sonceboz bipolar stepper motor (1,5A/phase max).
In particular we purchased DRV8811 evaluation board from TI, and all work fine. After that we've realized our customized PCB board, with the same components value and a similar layout, and some probems appear.
In the same conditions (current per phase, integer step, step ratio....), it seems that with our circuit the motor have frequently some step loss; also if we perform a sequence of single step we ear a different noise and steps appear not perfectly equals. In particular after each four steps sequence, it seems that motor have a position not perfectly stable, and we ear higher noise level. In all our test we are not able to reach the same behaviuor with DRV8811EVM and our board. Have you got some suggestion about it? Thank you very much.