0.5 V Current-Mode Low-Pass Filter Based on Voltage Second Generation Current Conveyor for Bio-Sensor Applications

Montree Kumngern,Tomasz Kulej,Fabian Khateb

doi:10.1109/access.2022.3146328

Abstract

This paper presents a low-voltage low-power current-mode third-order low-pass filter (LPF) based on voltage second generation current conveyor (VCII). The VCII utilizes the bulk-driven MOS transistor technique to achieve a wide input voltage range at low supply voltage of 0.5 V. Also, the VCII operates in the subthreshold region to achieve nano-power consumption of 390 nW. A third-order low-pass filter that is presented as an application of the VCII can operate as both current- and transimpedance-mode filters. The filter consumes 2.73 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> and the total harmonic distortion (THD) is below 1 % for sine-wave input signal below 350 nA <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pp</sub> @ 10 Hz. The post-layout simulation results based on TSMC 0.18 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS process are presented and confirms the futures of the filter.

Highlights

There is a gaining research interest for currentmode technique of the filter design
Compared with the voltage-mode counterparts the current-mode filters have been presented in the literature exhibiting improved performance [1]
This paper presents a third order low pass filter based on lowvoltage low-power VCII

Summary

INTRODUCTION

There is a gaining research interest for currentmode technique of the filter design. Conventional VCII has three terminals (y, x, and z), the first stage between y and x terminals is a current follower and cascaded by a voltage follower between x and z terminals as the second stage This device is designed to obtain a low impedance voltage output node for avoiding an extra voltage buffer for application requiring a voltage output signal [11]. These VCIIs are not suitable for applications to ultra-low power analog signal processing. A current-mode third-order low-pass filter based on voltage second generation current conveyor for biosensor applications is proposed. Post-layout Simulation results show that the filter offers a bandwidth (BW) of 250 Hz, and a power consumption of 2.73 μW

PROPOSED CIRCUIT

SIMULATION RESULTS The VCII was designed and verified in Cadence Analog

CONCLUSION