Low-sensitivity realization of switched-capacitor filters

Two low-sensitivity switched-capacitor filter structures implementing the strays-insensitive switched-capacitor biquads are presented. They are based on a generalized multiple-loop-feedback (GMF) topology, which is formed by the combination of the follow-the-leader-feedback (FLF) and inverse follow-the-leader-feedback (IFLF) topologies. Design equations that relate the feedback and feedforward parameters to the discrete-time transfer function are derived for both structures. Sensitivity analyses of the proposed structures as well as of the previously published ones are carried out using Monte Carlo simulations. It was found that the modified GMF structure possesses a lower sensitivity with respect to capacitance ratios.