Why there is no current chopping at the output coils during microstepping at lower STEP frequency input?

[siva2]

Posted on July 29, 2015 at 08:18

Dear Experts,

I am currently working with L9942 Driver IC. During micro-stepping at less than 700Hz of STEP frequency input to the driver, there is no current chopping at the output coils. At frequencies greater than 700Hz there is output for coils. The same is the case for other modes as follows:

1/4 mode: no currrent chopping at STEP frequency input less than 400Hz

1/2 mode: no currrent chopping at STEP frequency input less than 200Hz

 

Please help me understand the reason. 

#step-input-frequency