Complementary Metal-Oxide Semiconductor (CMOS) Circuit Realization of Elliptic Low-Pass Filter of Order (1 + α)

In this paper, complementary metal-oxide semiconductor (CMOS) circuit realization of a low-pass elliptic filter of order (1 + α) is realized using the inverse follow-the-leader feedback (IFLF) topology. The transfer functions to approximate the passband and stopband ripple characteristics of the second-order elliptic low-pass filter are synthesized using the nonlinear least squares (NLS) optimization routine. The elliptic filters of orders 1.4, 1.6, and 1.8 are designed using a cross-coupled operational transconductance amplifier (OTA) in the United Microelectronics Corporation (UMC) 180 nm CMOS process. The dynamic range of the filter was found to be 49.7 dB, 52.08 dB, and 54.02 dB for an order of 1.4, 1.6, and 1.8, respectively. The circuit simulation results such as magnitude, phase, transient, and group delay plots, are validated with the MATLAB simulation plots. Monte Carlo and PVT analyses have demonstrated the accuracy and robustness of the design. The proposed approach supports quality education and industry, innovation, and infrastructure.