DRV8824: Reducing the motor winding current

Hi Team,

Can you please help us with our customer's inquiry below.

I am working on a project where the driver DRV8824 and DRV8825 are used to control stepper motors.
Our application requires to reduce the motor windings current value (this is the holding current) when the STEP signal stops (no more rising edges). Therefore, after the STEP signal stops, we provide a xVref_hold smaller than the xVref_run. We expected to have the winding currents reduced in the same proportion, but this does not happen: the winding currents “freeze” at the levels corresponding to the xVref_run (the voltage applied before the STEP signal stopped).

We need your help to understand this behavior and potential solutions. We do not have control or early warning on the STEP signal stoppage

Regards,

Danilo