High-Performance Electronically Tunable Analog Filter Using a Single EX-CCCII

Abstract

In this paper, an electronically tunable mixed-mode analog filter is proposed, which employs only a single active element, namely Extra X Current Controlled Conveyor (EX-CCCII), two capacitors and a single resistor. The proposed circuit uses minimum components, so it is easy to integrate on chip. The circuit provides all four mode operations, namely current mode, voltage mode, transadmittance mode (TAM) and transimpedance mode without changing the circuit configuration. The circuit can provide all the five filter functions: low pass, high pass, band pass, band reject, and all pass by selecting appropriate input signals except the TAM. The parameters of the proposed circuit, i.e. angular frequency (ωo) and the quality factor (Q) are independent, while ωo is electronically tunable. The frequency range is 2.29 MHz to 22.9 MHz with a bias current variation from 1 to 100 µA. The effects of non-idealities and parasitics of the active element on the circuit performances are discussed. The results are verified through PSPICE simulation using a 0.18 µm CMOS technology with the supply voltages of ± 0.5 V. The power consumption is 13.5 µW at 1 µA, and 1.35 mW at 100 µA. The experimental setup further validates the theory and simulation results.