Novel A/D convertor with median filtering of programmable window length

Median filtering with programmable window length is needed for environments with impulse noises of different lengths. The authors propose a new architecture for an A/D convertor with median filtering of programmable window length. Both digital and analogue medians are available at the output. Previous architecture was implemented using a positive Boolean function (PBF) circuit which requires a large area for large window length. In this architecture, the majority circuit, which has a smaller area and faster speed, is used to replace the PBF circuit. The throughput is independent of the window size and the hardware complexity is linearly dependent on the window size. The silicon area of this architecture is small and it is therefore suitable for monolithic implementation using CMOS technology