On the design of low-frequency filters using CMOS OTAs operating in the subthreshold region

Duzenli G., Kilic Y., Kuntman H., Ataman A.

MICROELECTRONICS JOURNAL, vol.30, no.1, pp.45-54, 1999 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 1
  • Publication Date: 1999
  • Doi Number: 10.1016/s0026-2692(98)00084-6
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.45-54
  • Istanbul Technical University Affiliated: No


Design considerations on a circuit technique based on subthreshold operation of MOS transistors is described for the realization of low-frequency OTA-C active filters with small capacitance values of the order of 25-400 pF. The circuit technique described is applied to the alpha (8-12 Hz), beta (13-40 Hz), theta (4-8 Hz) and delta (1-4 Hz) band filters for EEG signals. Because of small capacitance values the filter circuit is suitable for realization on a single VLSI chip using the CMOS technology, and enables the user to implement the circuit on implantable biotelemetric applications. (C) 1998 Elsevier Science Ltd. All rights reserved.