A Second-order Sallen-Key Low-pass Filter with Switched Capacitors

This paper presents a second-order Sallen-Key low-pass filter structure that uses switch capacitors (SC) as equivalent substitutes for resistors. Two non-overlapping clocks can be generated through an external clock circuit, which can then control the MOS switch state and effectively replace the resistors in the filter, thereby achieving the goal of saving silicon chip area, improving integration, and optimizing circuit accuracy.