Hi there,
I need to work around a 53V limit of a LDO on a specific board by injecting it 40-ish volts, while the rest of the circuit gets full 65V.
And I'm a bit struggling to get 40V out of 65V in (somewhat) simple design.
Project requirements are these:
- sub 1mA quiescent current, ideally zero (this preregulator will be always connected to battery)
- at least 50mA output current (30mA expected maximum, with some reserves)
- stable output at 40V, regardless of what is the input voltage (always above 40V, but discharged battery will be 45V)
With such small currents, both LDO and switching regulators are good, but getting the quiescent current below 1mA is crucial.
I tried to play with TL783, but couldn't get anywhere, based on R2 value, it sucks up to 5mA from the source.
Is there a simple or ready-made solution for this?
Thanks!