DRV8434: not getting a sin wave current

I designed my driver based on the eval kit since I had tried my stepper motor with TI0 DRV8434 Eval kit and it was working just fine. Now when i monitor the Current sent to the motor by my driver board, i can only see a DC signal instead of the sine wave! and of Course motor doesn't move.  the step signal sent by MC looks fine. im using DRV8434 with 48V and 1.7Arms, 1/4 ustep and smart tune, ripple control.