Active Filter Design - Second Order Low Pass And High Pass

This study presents the design and simulation of a biquad active low-pass and high-pass filter employing a two-stage differential amplifier topology with a custom-designed operational amplifier. The proposed design utilizes switched capacitor circuits instead of traditional resistors, leveraging the advantages of switched capacitor technology, such as high precision and low sensitivity to process variations.The active filter architecture is implemented using Cadence Virtuoso in a 180nm technology node. Simulation results demonstrate the functionality and performance of the designed biquad active low-pass and high-pass filters. The filters exhibit desirable frequency response characteristics, including cutoff frequencies, passband gain, and stopband attenuation, meeting the specifications outlined for the project. The use of switched capacitor circuits enhances the filter’s performance, providing improved linearity and noise rejection compared to conventional resistor-based designs.