Originally Posted by H500  The design appears to use open loop pwm without current feedback. The microstepping likely won't be even. How well does it working? |
I investigated this chip as a replacement for the 297 becuase of the microstepping but simply put the current control simply doesnt work except in full and 1/2 step. If you want to use the other stepping modes you need to do the sense voltage comparison and externally. As it says in the datasheet:
"Peak current feedback control using pulse width modulation chopping can only be used in full-step or half-step modes..... In all other
modes, the VREF input should be set to VDD and the sense inputs should
be grounded."
When i spoke to LSI on this they explained its because the blanking time from the monostable is too long except in 1/2 and full step operation.