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Superficies y vacío

Print version ISSN 1665-3521

Superf. vacío vol.22 n.4 México Dec. 2009


Weak–inversion topologies of analog median filters


Alejandro Díaz–Sánchez1, José Miguel Rocha Pérez1, Javier Lemus–López1, Jaime Ramírez–Angulo2*, Germán Ardul Muñoz–Hernández3, Carlos Arturo Gracios–Marín3


1 INAOE, Luis E. Erro #1. Tonantzintla, Puebla, México. E–mail:,

2 Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, New Mexico, USA. E–mail:: *

3 Instituto Tecnológico de Puebla Av. Tecnológico 424, Puebla, Puebla, México. E–mail:


Recibido: 10 de julio de 2009.
Aceptado: 20 de octubre de 2009.



Design and implementation of two analog median filter cells are described. The first topology is a differential pairs array, which drain currents are driven into two nodes in a differential fashion. The second topology is based on a wide range OTA, which is used as basic block to maximize the dynamic range. Fabrication parameters for a MOSIS process of 1.6 μm are used. Experimental results of two three–input fabricated prototypes are shown.

Keywords: Non–linear Filters; Median Filters; Weak–Inversion.





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