Stray insensitive programmable switched-capacitor filter

A universal programmable switched-capacitor (SC) filter is presented. The network is based on the generalized immittance converter (GIC) configuration, known for its excellent passive and active sensitivities. CMOS switches were used for element relocation to digitally control and realize different filter topologies. Switches were also used to control banks of binary weighted capacitors that determine the filter center frequency and quality factor. The bilinear transformation was used in the SC implementation of filter resistive elements. Extra care was taken in the design procedure to minimize the effect of the stray capacitors on the network transfer functions. The result was a general-purpose digitally programmable biquadratic section that can equally compete with the best available stray insensitive filters and inherit the low active and passive sensitivities of the GIC