Wide-range electronically tunable multifunctional OTA-C filter for instrumentation applications

A simple scheme is presented for realizing four standard second-order transfer functions, i.e. low-pass, high-pass, bandpass, and band-elimination. The system is implemented using only operational transconductance amplifiers (OTAs) and capacitors. The resulting circuit has the attractive feature of wide-range electronic tuning of pole frequency, bandwidth, and pole Q. These parameters may also be programmed digitally. The OTA-C filter achieves excellent sensitivity performance and is suitable for monolithic IC implementation.