Forums

biquad over butter

Started by joeDiHare September 5, 2010
Hi all.
I am trying to understand what the benefit would be of having a biquad
instead of a butterworth filter in analogue implementation. For example, if
I assume that -more or less- i need 2 integrating capacitor per pole, then
i need the same for both a 8th order butterworth or a 4th order biquad
(e.g. a OZGF). Therefore, they have the same cost, right? Is there any
application where a biquad is prefereable to a buttenworth??
Thank you very much.



joeDiHare wrote:

> Hi all. > I am trying to understand what the benefit would be of having a biquad > instead of a butterworth filter in analogue implementation.
Butterworth is a transfer function. Biquad is a circuit topology.
> For example, if > I assume that -more or less- i need 2 integrating capacitor per pole, then > i need the same for both a 8th order butterworth or a 4th order biquad > (e.g. a OZGF). Therefore, they have the same cost, right? Is there any > application where a biquad is prefereable to a buttenworth??
Biquad topology is preferred for the high Q poles.
> Thank you very much.
You don't have to thank me. Just $100 would be enough. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com