A 1.8 V Gm-C Highly Tunable Low Pass Filter for Sensing Applications

Abstract

This paper presents a fully integrated, first-order Low Pass Filter with 2-tuning points giving a wide versatility to the filter. It allows for a fine/thick tuning with a cutoff frequency that spans over several orders of magnitude, from 220 mHz to 39.1 kHz. The Gm-C filter proposed is designed in a 180 nm CMOS technology with a total power consumption of 1.08 µW for a 1.8 V power supply and a dynamic range up to 73 dB. The proposed filter is a very competitive solution compared with previously reported works, meeting the requirements for portable on chip sensor interfaces based on impedance spectroscopy and biosignal front-end interfaces.