Wide tunable all pass filter using OTA as active component

A new tunable all pass filter is presented. It is based on the simple op-amp based filter with a programmable floating capacitor and a programmable resistor. The proposed floating capacitor value can be widely varied by adjusting the transconductance parameter which depends on bias current. The floating capacitor consists of only five OTAs. Using simulation results a first order all pass filter with phase tuning capability is proposed.