Novel Current-Mode Active-Only Biquad With Loss-Less And Lossy Integrators

This paper presents a realization of a current-mode active-only biquad with a two-integrator loop structure. The proposed circuit is constructed solely with operational amplifiers (OAs) and operational transconductance amplifiers (OTAs). The circuit can realize low-pass, band-pass, high-pass, band-stop and all-pass transfer functions, and the circuit characteristics can be electronically tuned by adjusting the transconductance gains of the OTAs. An example is given together with simulated results by PSPICE. The circuit configuration is very suitable for implementation in both bipolar and CMOS technologies.