Another potential problem is that the cascaded emitter follower circuit
shown is likely to oscillate in the VHF region.
An unbypassed resistor in series with the base of each emitter follower
should be used.
Bruce
Bruce Griffiths wrote:
Omitting the output bypass cap in the single transistor Wenzel
cancellation circuit is somewhat misleading in that it reduces the
high frequency attenuation,
All his other circuits include such caps.
A simple tweak (adjusting a resistor ratio) which makes the shunt
transistor collector current approximately PTAT significantly reduces
the temperature dependence of the cancellation.
Bruce
Bob Camp wrote:
Hi
Interesting site - Thanks!
A couple of observations:
There are a couple of circuits (low noise op-amp based) that can
generate lower noise than what he's shown.
You need to be careful looking at his results. A lot of what he shows
is the result of changing the model used for the output capacitor….
Still well worth looking at.
Bob
On Nov 22, 2011, at 7:07 AM, Ulrich Bangert wrote:
Gentlemen,
i would like to draw your attention to this site:
http://pstca.com/spice/ripple/ripple.htm
The author of this site thank-worthy not only presents circuits for
power supply finesse but also simulates them with SPICE. It seems to
turn out as if the well known Wenzel suggestions for voltage
regulator finesse were not state of the art and other circuits
(although similar in principle) may easily outperform them.
Best regards
Ulrich Bangert
Ortholzer Weg1
27243 Gross Ippener
Deutschland
Tel +49 (0)4224 95071
Fax +49 (0)4224 95072
Mob +49 (0)172 8006546
www.ulrich-bangert.de
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
