Hi Nick,
Slow decay can act this way. It depends on the system voltage, the motor inductance, the blanking time, the off time, and the step speed.
In slow decay, the DRV8711 is injecting more current during tblank than the off time can remove. In the next drive cycle the current continues to increase until an equilibrium is reached.
Automixed decay prevents this loss of current regulation from occurring by adding a portion of mixed decay in each off cycle. You may be able to do the same thing by increasing the off time, but that may cause audible noise if you have to increase toff too much.
Slow decay can act this way. It depends on the system voltage, the motor inductance, the blanking time, the off time, and the step speed.
In slow decay, the DRV8711 is injecting more current during tblank than the off time can remove. In the next drive cycle the current continues to increase until an equilibrium is reached.
Automixed decay prevents this loss of current regulation from occurring by adding a portion of mixed decay in each off cycle. You may be able to do the same thing by increasing the off time, but that may cause audible noise if you have to increase toff too much.