LDO after DC/DC switched capacitor stage: line and load reg, what else that matters?

[allennlowaton]

hello guys.

I'm having this project now. My DC-DC switched capacitor is followed by the LDO for regulations. I had observed that the line and load regulations are doing well.
My question now, is what other criteria that I need to looked into aside from the two regulations.

Thank you.

 

[leo_o2]

Efficiency, output voltage ripple, line/load response, PSRR, quiescent current.

 

[dick_freebird]

The PSRR at switching frequency and its first few harmonics
is the big deal as far as noise goes. Many PMOS LDOs have
poor HF PSRR, since they have a lot of through-capacitance.
So you will need a very stiff output capacitor to divide that
away, and many LDOs don't like super low ESR caps on the
output.

 

[leo_o2]

I guess he will use NMOS LDO for better efficiency.