An electronically controllable floating capacitor multiplier for low frequency applications

Abstract

In this study, a floating capacitor multiplier structure without any passive resistor, created using a subtractor and a multiple-output current differencing transconductance amplifier (MO-CDTA), is extensively analyzed. In this respect, the characteristic equations, operating principles, and filter applications of the structure examined are provided. For the floating capacitor multiplier structure, multiplication factor ‘k’ varies between 400 and 1200 depending on the $V_{\text{GS}}$ voltage. Besides the tunability feature, another striking aspect of this work is the applied of three different filter structures due to the floating configuration. The cut-off frequency of the low-pass filter created with the floating capacitor multiplier ranges from 12.5 kHz to 32.6 kHz. Another application, the high-pass filter, has a cut-off frequency ranging from 58.4 kHz to 207.3 kHz. In the final band-pass filter structure applied in this study, it is demonstrated that the center frequency of filter ranging from 15.5 kHz to 33.5 kHz is suitable for low frequency operations due to the structure's tunable feature. In addition to filter applications, post-layout details including temperature, Monte Carlo, and total harmonic distortion analysis of the proposed capacitor multiplier are provided alongside the experimental results.