A voltage-mode fully cascadable biquad with three CFOAs and grounded capacitors

In this paper, a new voltage-mode second-order multifunction filter with three current feedback operational amplifiers is developed. This circuit generates low-pass filter, band-pass filter (BPF), inverting-type BPF, notch filter, and all-pass filter (APF) responses with all gains. It has high input and low output impedances for all the filter responses. It also has the advantage of grounded two capacitors, which is essential for integrated circuit technology. It has orthogonally controllable features for all the filter responses except the APF one. However, one passive element matching condition is needed to obtain an APF response. Many simulations are carried out via the SPICE program, where 0.13 µm technology parameters are utilized. Furthermore, a few experiments are performed using the AD844s to see the performance of the developed filter in practice.