Analysis and synthesis of switched-capacitor state-variable filters

The design and analysis of switched-capacitor filters of the state variable or "leapfrog" type is presented in which the sampling rate may be as low as twice the highest frequency of interest. The effects due to the sampled data nature of the signals are fully taken into account and an exact synthesis is derived. This allows the sampling rate to be treated as a design parameter which Influences the maximum attenuation level in the stopband and the required capacitance ratios.