Single Topology-Based Reconfigurable Positive and Negative Immittance Circuit and its Application as Multifunction Filter and Quadrature Oscillator

This paper reports a reconfigurable positive and negative immittance circuit using single topology built with Operational Transconductance Amplifier (OTA). The purpose of this paper is to introduce a reconfigurable positive and negative immittance circuit using minimum number of active and passive components. Changing the gate voltage of MOS switches makes it simple to flip between positive and negative operating modes. The designed circuit employs only one grounded capacitor as a passive component, which makes it compatible with current integration technologies. Layout area of the designed immittance circuit is 50.1[Formula: see text][Formula: see text]m. Nonideal impact of OTA on the proposed circuit is also evaluated mathematically. In addition, resistorless single topology-based reconfigurable multifunction filter and quadrature oscillator circuits are also designed using proposed immittance circuits. The values of cut-off frequency of multifunction filter and oscillating frequency of quadrature oscillator may be tuned via modifying the transconductance of OTA. Monte Carlo and PVT analyses of the proposed circuits are illustrated to show the robustness of the designed circuits. The functionality of the designed circuits is demonstrated by SPICE simulation based on the 90[Formula: see text]nm CMOS process parameter.