[time-nuts] Parallel voltage regulators

[Bruce Griffiths]

Poul-Henning Kamp wrote:
> Considering the efficiency and easy availability of switchmode
> supplies these days, I would never bother with a linear regulator
> in a new design.
>
> For instance national has a series of switch mode regulators (LM25xx)
> which just requires a coil and a diode more than the usual LM78xx
> types.
>
> If you are worried about noise from the swichmode, you can add more
> filtering to the output.
>
>   
That is a recipe for disaster if one wants a really low noise oscillator.
This is particularly true if one is a beginner.
Reducing the output noise of a switching regulator to 100uV rms or less
is neither easy nor simple.

Bruce