Electronically tunable resistorless capacitance multiplier employing VDBAs

Abstract

This work focuses on a circuit configuration for the simulation of the resistorless tunable grounded capacitance multiplier using the recently introduced active building block called voltage differencing buffered amplifier (VDBA). The proposed capacitance multiplier circuit consists of only two VDBAs, and one floating capacitor, without requiring critical matching conditions. The realized equivalent capacitance value can be tuned electronically through the ratio of the transconductance gain of the VDBA. The effect of the VDBA non-idealities on the realized equivalent capacitance has also been investigated in detail. As an application, an illustrative RLC low-pass filter using the proposed tunable capacitance simulator has been provided. In order to demonstrate the behavior of the circuit and confirm the theory, PSPICE simulation results with TSMC 0.25-µm CMOS technology are included.