Please recommend other Pre-regulator Topologies

Hello everyone.

I'm working with a CMOS voltage reference and like to add a pre-regulator for PSRR enhancement. I have read Mora's book on Voltage References and the attached image is one of its design examples. Can anyone refer me to other topologies of pre regulator circuits, if any?




Also, I'd like to avoid using opamps.

Additional Info:
I'm using 0.18um CMOS library.

Thanks,
rmanalo

Begin with what you want from the preregulator. DC PSRR
is a datasheet number that people look at, but has limited
value in many modern applications; HF PSRR matters a lot
to RFICs, POL regulators etc (these latter may care about
both).

Top sketch is good for HF PSRR, better if you added a
NMOS source follower and decoupled its gate to ground.
You might improve HF PSRR more by adding some cascodes
in the reference stacks to shield supply-ground difference
noise.

Bottom figure will be better for DC PSRR but the loop will
almost certainly peter out before your signal path gain
does. Although mp3 gate lacks a high-going drive / bleed
and so might have dismal HF behavior.

Sounds like the application favors DC PSRR but you
need to "ask your clients" what kind of vref hf supply
rejection they need to see.