Not clear to me how the PMBus control and the Ext resistor work together.
I assume we have to use an external R to set the nominal, otherwise will start up the first time at 0.5v and it won't be able to turn on the downstream component.
- We want a 0.9v default and expect to adjust down to 0.85 via PMBus.
I can put a 12.1K res on the RSet to get 0.9 nominal. But not clear if that changes the mapping from code to voltage on the VOUT register.
- Will it still be Vout = code * 512?
- Will the PMBUS host do the right thing to adjust the output voltage even with the RSet in place (does PMBus override the Rset value)?
Thanks,
Nick
