Compact continuous-time analog rank-order filter implementation in CMOS technology

A simple CMOS implementation of a continuous-time analog rank-order N input filter is presented that uses N operational transconductance amplifiers. Rank is digitally programmable for all values from k=1 (min case) to k=n (max case). The implementation is based on a compact transconductor with high transconductance gain and symmetrical output current saturating characteristics. Experimental and simulation results are presented that verify functionality and the high frequency characteristics of the proposed implementation.