An obvious in retrospect but brilliant means of achieving additional 
power supply noise reduction. Especially useful in switching power 
supplies where output noise may be an issue. Could probably be staged 
for additional effect but would be with diminishing returns.

Claims 26 dB improvement at low frequencies. Better results could be 
obtained with suitable attention to detail and superior components.

http://www.planetanalog.com/showArticle.jhtml?sssdmh=dm4.159974&articleID=174900405

Circuit: http://i.cmpnet.com/planetanalog/2005/12/C0024-Figure1.gif

Noise performance: 
http://i.cmpnet.com/planetanalog/2005/12/C0024-Figure2.gif


        RM

____________________________________

Ref: Ken Mardle:


Ken says:

> Same approach could probably be used (at expense of increased power
> consumption) to allow smaller reservoir C's by cancelling ripple.

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist