A Video Selectivity Block for Television Receivers

The trend towa-rds miniaturization of the video circuits in the television receivers suffers due to the presence of a large number of passive filters. Further miniaturization leading to a possible video LSI can be thought of only when these filters are made active. The frequency range of operation of these filters excludes the use of operational amrlifiers as active elements for their realization. CMOS arrays with their ease of fabrication and simplicity of use come as handy alternatives. A video selectivity block consisting of a chroma bandpass filter, a chroma notch filter and a sound bandpass filter which also includes a stabilization scheme to desensitize the performance factors of these filters against variations in supply voltages and temperature is suggested. The block is suitable for monolithic fabrication.