[time-nuts] Low noise power supplies?
Rex
rexa at sonic.net
Thu Jan 31 04:01:24 EST 2013
On 1/31/2013 12:20 AM, Bruce Griffiths wrote:
> With some care its possible to make the emitter current of the shunt
> transistor approximately PTAT so that, at least for small signals the
> temperature dependence of the rejection is reduced significantly.
Sorry, what does PTAT mean? I'm not familiar with that term.
>
> Its also possible to build a feedback style shunt regulator that has
> considerably higher supply rejection than the Wenzel circuit using an
> opamp and a shunt transistor together with a small resistance in
> series with one of the supply leads.
>
> Bruce
The Wenzel article gives three circuit topologies. The third shows an
opamp feeding a 2N4401 across 0.05 ohm in the power path. Sounds like
what you are describing. Did you miss that one or are you describing
something different?
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