[sdiy] feedback cap formula?

[TIm Daugard]

> > typical inverting opamp situation ? is it 2*pi*Rf*Cf ?  is the cap's value

I relooked at the e-mail. The formula is C = 1 / ( 2*pi*R*F) where R is the
parallel feedback resistor; or the internal impedance of the opamp feedback
path, if you run the opamp without a feedback resistor. The easiest way to
determine the feedback capacitor, without a feedback resistor, is to breadboard
the circuit an measure the response. Substitute the capacitor until you get the
response you need.

I calculated, then breadboarded to get the 51 pf I use with the TL072 and TL074.

Tim Daugard