why the fault output of TMC6200 is pulsed waveform instead of high (continuous)?

Question

We are using TMC6200 driver IC for motor control to run the Permanent Magnet Synchronous motor. PWM pulses are generated from Digital signal processor. after running for some time we are getting this kind of waveform (as attached). But when we try to read the fault registers few times we are getting the flag - under voltage for charge pump but some times there is no fault. Let us know in what condition fault pin shows this kind of signal. 
 Thanks.

BernhardDwersteg · Accepted Answer

Hi, 
 undervoltage of charge pump should not happen, unless you have a very low supply voltage. In most cases it is a sign for too high ripple on the VS terminal / on the positive terminal of the charge pump capacitor. This will overload the internal charge pump. Please provide more capacity on VS, or apply a small RC filter for VS terminal and positive end of charge pump capacitor. This should solve the issue.)

Partner Forums

Partner Libraries

why the fault output of TMC6200 is pulsed waveform instead of high (continuous)?