Spectral analysis of double-sampling switched-capacitor filters

The double-sampling scheme (DSS) design technique is suitable for the realization of high-frequency switched-capacitor (SC) filters. This design technique effectively doubles the applicable frequency range of standard bi-phase SC filters. In practice, the particular nonideal properties of the double-sampling scheme result mainly in parasitic sidebands in the output spectrum. The DSS design technique is described, and a spectral analysis of double-sampling SC filters, including the nonideal properties, is given. With these results, the precise specifications for the pre- (anti-aliasing) and postfilter are derived. An excellent match between the analytical description and experimental results is found for a linear fifth-order elliptic double-sampling SC low-pass filter designed for video frequency applications