CMOS Analog Rank Order Filters using positive feedback comparators

This work presents the design and experimental results of two Analog CMOS Rank Order Filters (ROF's), both of them based on the same operation principle and working with a specific analog CMOS comparator. The design of the two ROF's were performed with ON Semi 0.5µm CMOS technology through MOSIS. Both comparators present a high gain due to the use of positive feedback. An Slew Rate (SR) of 2.6V/μs@30pF, including the parasitic capacitances of the experimental measurements setup, is shown. •This work presents two analog Rank Order Filters (ROFs) each one based on the same scheme.•The filtering scheme allows a current-based programmable statistical order according to the desired one.•Each ROF uses as basis a corresponding positive feedback analog comparator.•The positive feedback comparators achieve a response of 2.6V/μs@30pF.•Both ROF successfully works experimentally and also fulfill the design requirements.