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Design >> Analog Design >> SC filter implementation problem
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Message started by rampat on Dec 19^th, 2007, 12:06am

Title: SC filter implementation problem
Post by rampat on Dec 19^th, 2007, 12:06am

HI all,

0.49496 (z-0.999) (z-0.9973)
I have z-domain transfer fucntion H(z)= ---------------------------- .I want implement it using SC biquad filters in VLSI.But the problem
(z-1) (z-0.9777)

is ,since all zeros and poles are very close it each so the system is very sensitive cap ratios in the sc filter implementation and also max capacitor spread=88 .Can anyone please stress on the criticality of the system or where else can I implement this system which is less sensitive?How can I reduce the cap spread?

regards
rampat

Title: Re: SC filter implementation problem
Post by Berti on Dec 19^th, 2007, 10:55pm

Hi,

The implementation H(z) might indeed be problematic.
I think you should start optimizing at system level, not circuit level.
Do you really need a transfer function like this? Or is there an other,
roboust solution.

Regards