Resistorless tunable capacitance multiplier using single voltage differencing inverting buffered amplifier

Abstract

The paper focuses on a novel configuration for the realization of the resistorless tunable grounded capacitance multiplier circuit using the newly introduced active building block called voltage differencing inverting buffered amplifier (VDIBA). The proposed capacitance multiplier circuit consists of only single VDIBA, one capacitor and one NMOS transistor acting as a voltagecontrolled resistor (VCR). The equivalent capacitance value of the synthetic capacitor can be tuned electronically by adjusting the biasing current of the VDIBA and/or changing the control voltage of the VCR. To evaluate the behaviour of the circuit, an illustrative RC low-pass filter has been provided. Simulation results with TSMC 0.25 μm CMOS technology verify the theoretical analysis.