CMOS Analog Rank Order Filters using positive feedback comparators

• Published in: Integration (Amsterdam) Vol. 58; pp. 111 - 115
• Main Authors: Bandala-Hernandez, H.C., Díaz-Sánchez, A., Rocha-Pérez, J.M., Ramírez-Angulo, J., López-Ortega, I.Y., Lemus-López, J., Molinar-Solís, J.E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-06-2017; Elsevier BV
• Subjects: Analog; Analog comparator; CMOS; Comparators; High gain; Image processing; Positive feedback; Rank order; Slew rate; Studies; 99-00; 00-01; Image processing; Analog comparator; Rank order
• ISSN: 0167-9260; 1872-7522
• DOI: 10.1016/j.vlsi.2017.02.005

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.