Input Signals EVALSTDRIVE101 in ENx/INx Mode

[meltabo]

Since I'm not allowed to work with Motor control library, I need to generate the output signals for EVALSTDRIVE101 on my own. Apparently it does not work when I put PWM signals on INx and 3.3V on ENx. (Of course I selected mode INx/ENx). From what I read in the datasheet, this should be exactly what I need to do, enable all the half bridges ENx by putting 3.3V and then feeding the PWM signals on IN_U, IN_V and IN_W, which correspond to the voltages for each phase. Subsequently STDRIVE101 is generating the signals GLSx and GHSx in the correct way.

What am I missing?

In MCSDK I can only find examples where INxH/INxL is enabled. I try to do pattern matching, but there is no examble for ENx/INx mode of the STDRIVE101.

[Cristiana SCARAMEL · Accepted solution]

Hi @meltabo​,

What hardware are you using to generate PWM signals?

In any case, the device use a bootstrap technique to generate a voltage higher than the supply VS needed to supply the high-side drivers.

During the power-up (or after leaving the standby condition), there may be no charge in bootstrap capacitors.

In these cases, the drivers cannot start immediately with normal operation, but the bootstrap capacitor should be charged turning on the low-side MOSFET.

If you not charge the bootstrap capacitors the high-side drivers cannot turn-on the related MOSFETs.

You can find more details on the STDRIVE101 datasheet (starting from page 15).

Let me know if this info is useful to solve your problem,  if so please "Select as Best" label.

[Cristiana SCARAMEL]

Hello @meltabo​ any feedback about your question?

[meltabo]

It was not quite what I asked for, but informative anyway, because after I was able to get the board running I had a Fault at startup quite some time which relates to what you answered.