The Biquad consists of two successive integration stages followed by an inverting stage. The entire group has a feedback loop from the front to the back consisting of R1 which is chiefly responsible for controlling the center frequency, ‰o. The first stage of integration is a poor integrator because R2 limits the range of integration. R2 and C fo

rm the time constant of the first stage integrator with R3 influencing gain H almost directly. The band-pass function is taken after the ftrst stage with the lowpass function taken after the third stage. The remaining ftlter operations are generated by various combinations of three stages. The Biquad is orthogonally tuned, meaning that ‰o. Q. and gain H can all be independently adjusted. The component values known will allow ‰o, to range from 40 Hz to 20 kHz. The other component values give an adequate range of operation to allow for virtually universal filtering in the audio region. ‰o Q. and gain H can all be independently adjusted by tuning R1 through R3 in succession.

Leave Comment

characters left:

New Circuits