How do switched-capacitor circuits work and what are the design considerations?

Switched-capacitor (SC) circuits use capacitors and switches (clocked MOSFETs) to emulate resistors: R_eq = 1/(f_clk * C). Advantages include precise ratios (capacitor matching > resistor matching in ICs), tunability via clock frequency, and no continuous power dissipation in equivalent resistance. Design considerations: Clock feedthrough (charge injection from switches, mitigate with complementary switches, bottom-plate sampling), Finite op-amp gain (causes gain error), Op-amp settling time (must settle within clock phase), kT/C noise (limits minimum capacitor size: noise = kT/C), and Non-overlapping clock generation. SC filters and ADCs are ubiquitous in mixed-signal ICs.