Hello,
we are building a custom PCB using the nPM1300. We need a low-noise 1V8 rail for a sensitive analog component and are wondering what the best setup for that would be.
We would like to use the nPM1300's LDO do achieve a low noise rail. With the nPM1300 we would have two options:
1) Set one of the BUCKs to 3V3, and use that to power the LDO
2) Power the LDO directly from VSYS
I would assume that option 2) would result in less noise, but it might also mean a higher idle power consumption since the drop from VSYS to 1V8 will be higher than from the fixed 3V3 BUCK rail to 1V8. As such, option 1) might be more power efficient. What do you think and which option would you recommend?
I was also looking to find out what kind of noise and noise rejection the LDOs in the nPM1300 have, but was unable to do find any measurements. Do you have any information there?
