Applications of CCD and switched capacitor filter technology

Basic principles of CCD and switched capacitor sampled-data filters are reviewed along with improvements in CCD filter fabrication and output circuit techniques. The CCD chirp-z transform (CZT) for performing the discrete Fourier transform with CCD filters is presented. This technology was used in the development of a self-contained 32-point and 512-point CZT IC which illustrates the capability of combining CCDs, clock drivers, multiplying d/a converters and amplifiers in a single IC. The application of combined CCD and switched capacitor filters to perform speech analysis and synthesis for a vocoder is described. Consideration is given to developments in programmable devices and applications of monolithic filters.