emma1997 wrote: ↑
Sun Dec 22, 2019 11:23 pm
I wonder if it's possible to tack on a 3.3v and 1.8v regulator. Dirt cheap and certainly less than a new Pi.
Or have designers gone too far protecting us from ourselves again and made it impossible from a firmware or software viewpoint?
No, it is not possible -- at least not without removing the existing regulator (non-trivial). Some people with suitable rework stations seem to have succeeded in like-for like replacement, but AIUI the PMIC is a pre-programmed part specifically for the Raspberry Pi, therefore difficult to source.
It's not that the designers have deliberately made life difficult, it's more that external regulators need to abide by precise sequencing of the power rails, and such a circuit (other than direct part replacement) is not dirt cheap, and is not worth developing on a one-off basis.