Signal-flow graph OTA-C band-pass and band-reject integrated filters

A simple and straightforward method for the synthesis of OTA (operational transconductance amplifier) -C bandpass and band-reject filters is presented. The method mixes the signal-flow-graph and component-simulation techniques. The final filters have good sensitivity performance and all capacitors grounded, which are advantages for integration. The method can be applied to the OTA-C simulation of any ladder passive prototype filter. Problems related to the presence of nonobservable poles created by the structure of these filters are discussed, and solutions are proposed.<>