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Design >> RF Design >> layout the elliptic gm-C filter
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Message started by edward.yin on Aug 8^th, 2007, 1:53am

Title: layout the elliptic gm-C filter
Post by edward.yin on Aug 8^th, 2007, 1:53am

hi,all

after I finished the schematic of a elliptic Gm-C filter, what requirement should I take into account when I layout the filter, is there anyone who can give me some advice about that?

thx in advance!

Title: Re: layout the elliptic gm-C filter
Post by ACWWong on Aug 9^th, 2007, 8:00am

For an elliptic gmC filter where pole Q is normally quite high you will be more prone to layout parasitics fouling up your reponse/gain. So pay attention to parasitic R (short tracks not too narrow, ensure good via coverage where needed) as well as C (use higher level metals) and an post layout extracted simulation is a must to check the performance.
Also be aware non-schematic items like antenna diodes which may not be extracted from the layout.

I guess its differential so of course pay attention to symmetry. Anyway try the excellent book by Alan Hastings "The Art of Analog Layout".