Analog Integrated Circuits and Signal Processing

, Volume 74, Issue 2, pp 473–478 | Cite as

Compact SC frequency tuning circuit for continuous-time Gm–C filters

  • T. Sánchez-Rodríguez
  • F. Muñoz
  • J. Galán
  • A. Torralba
  • R. G. Carvajal
Mixed Signal Letter

Abstract

A novel automatic frequency tuning circuit for continuous-time filters is presented. Based on the switched-capacitor technique, the circuit offers an advantage in terms of simplicity resulting from the use of only two matched current sources, an operational amplifier with relaxed specifications and a transconductor that is a replica of the filter transconductors. Despite the simplicity of the scheme, the accuracy of the system is less than 1 % of frequency error. The circuit has been designed in a 0.5 μm CMOS technology with a 3.3 V power supply and simulation results confirm the suitability of the proposed approach.

Keywords

Automatic frequency tuning Switched-capacitor technique Transconductor Gm–C filters Low power 

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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • T. Sánchez-Rodríguez
    • 1
  • F. Muñoz
    • 2
  • J. Galán
    • 1
  • A. Torralba
    • 2
  • R. G. Carvajal
    • 2
  1. 1.Dpto de Ingeniería Electrónica, de Sistemas Informáticos y AutomáticaUniversidad de HuelvaHuelvaSpain
  2. 2.Dpto de Ingeniería Electrónica, Escuela Superior de IngenierosUniversidad de SevillaSevilleSpain

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