Phase Correction Using Single Current Feedback Amplifier

This paper presents a novel realization scheme for a single-CFA (Current Feedback Amplifier) [1] based simple first-order All-Pass Filter (APF) with a grounded capacitor. The proposed topology has been further developed to achieve a second-order design by incorporating a grounded shunt LC-resonator as the phase-selection component. This extension utilizes a single DVCCTA (Differential Voltage Current Conveyor Transconductance Amplifier) [2] based L-simulator is employed to realize the LC-resonator. The impact of device imperfections, including port tracking errors and parasitic capacitors (Cy,z), on the phase responses has been analyzed, revealing a negligible effect. The design maintains a flat unity gain across the intended frequency range, although the usable frequency range is limited by Cy,z. Experimental verification up to 2.4MHz shows measured Total Harmonic Distortion (THD) of the output signal at 0.9% and 2.7% for the first-order and second-order APF, respectively.