Title: 0.5 V, 5 MHz active-RC biquad filter in 90 nm CMOS technology

Authors: S. Rekha; T. Laxminidhi

Addresses: Department of Electronics and Communication Engineering, National Institute of Technology Karnataka, Surathkal, 575025, India ' Department of Electronics and Communication Engineering, National Institute of Technology Karnataka, Surathkal, 575025, India

Abstract: This paper proposes a low voltage, low power active-RC biquad filter operating on a power supply voltage of 0.5 V in 90 nm standard CMOS technology. A CMOS inverter-based transconductor is used as the building block. A sub-threshold model is developed for the transconductor as the transistors are operating in sub-threshold region. A feed-forward compensated OTA is designed using this transconductor and is used to realise the filter. OTA exhibits an open loop DC gain of 61.89 dB and a unity gain bandwidth of 1.35 GHz. It is stable with a phase margin of 52.85°. Power consumed by the OTA is as low as 29.91 µW. The designed filter has a cut-off frequency of 5 MHz and offers a dynamic range of 55.78 dB with a figure of merit of 0.022 fJ. Power consumed by the filter is 58.76 µW.

Keywords: CMOS; inverters; transconductors; operational transconductance amplifier; OTA; feedforward compensation; active-RC biquad filters; dynamic range; figure of merit; FOM.

DOI: 10.1504/IJCAD.2016.082134

International Journal of Circuits and Architecture Design, 2016 Vol.2 No.2, pp.142 - 154

Received: 01 Jul 2015
Accepted: 27 Dec 2015
Published online: 08 Feb 2017 *

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