Current-mode first-order allpass filter employing single current operational amplifier


KILINÇ S., ÇAM U.

ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING, vol.41, no.1, pp.47-53, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 41 Issue: 1
  • Publication Date: 2004
  • Doi Number: 10.1023/b:alog.0000038282.60137.5f
  • Journal Name: ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.47-53
  • Keywords: current-mode circuits, allpass filter, current operational amplifier, ALL-PASS, REALIZATION
  • Dokuz Eylül University Affiliated: Yes

Abstract

A current-mode first-order allpass filter configuration is proposed. The presented circuit uses a single current operational amplifier (COA), a resistor and a capacitor, which are of minimum number. High output impedance of the proposed filter enables the circuit to be cascaded without additional buffers. The proposed circuit is insensitive to parasitic input capacitances and input resistances due to internally grounded input terminals of COA. It does not impose any component matching constraint in analog signal processing circuits. Non-ideal effects of COA to the first-order allpass network are also investigated. To demonstrate the performance of the proposed filter a new current-mode quadrature oscillator is given as an application example. The theoretical results are verified with PSPICE simulations using a new realization of fully differential CMOS COA.