New Tunable CFOA-Based Positive Group Delay Cascadable Circuit
Muhammad Taher Abuelma’atti and Munir A. Al-Absi
This paper presents a new current-feedback operational-amplifier (CFOA) based first-order voltage mode all-pass filter (APF). The proposed circuit can be used as a tunable time-delay circuit with relatively large time delays. The circuit enjoys low output impedance and, therefore, can be easily cascaded with similar circuits to obtain larger time delays. The functionality of the circuit was confirmed using PSPICE simulation tool and commercially available integrated circuit (AD844). The simulation results show that delay can be tuned from 10μs to 256μs.
Keywords: current feedback operational amplifier, inductance emulator, all pass filter, time delay circuit.