Cascadable allpass and notch filters employing single operational transresistance amplifier

KILINÇ S., ÇAM U.

COMPUTERS & ELECTRICAL ENGINEERING, vol.31, no.6, pp.391-401, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: 6
  • Publication Date: 2005
  • Doi Number: 10.1016/j.compeleceng.2005.06.001
  • Journal Name: COMPUTERS & ELECTRICAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.391-401
  • Keywords: allpass filter, notch filter, operational transresistance amplifier, DIFFERENCING BUFFERED AMPLIFIER, ALL-PASS
  • Dokuz Eylül University Affiliated: Yes

Abstract

A new voltage-mode filter configuration is proposed. The presented topology uses single operational transresistance amplifier (OTRA) and can realize first-order allpass, second-order allpass and notch filtering functions. The proposed circuits are insensitive to parasitic capacitances and resistances due to internally grounded input terminals of OTRA. Low output impedance of the configuration enables the circuits to be cascaded without additional buffers. The theoretical results are verified with PSPICE simulations using a CMOS realization of OTRA. Experimental work is also carried out. The feasibility of the proposed first-order allpass filter is illustrated on the design of a quadrature oscillator. (c) 2005 Elsevier Ltd. All rights reserved.