A method to design high SNR nanoscale magnetic sensors using an array of tunnelling magneto-resistance (TMR) devices

doi:10.1088/0022-3727/40/15/002

A method to design high SNR nanoscale magnetic sensors using an array of tunnelling magneto-resistance (TMR) devices

Author

P Gomez ¹, D Litvinov ² and S Khizroev ³

Affiliations

¹ Department of Electrical Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174, USA
² Department of Electrical Engineering, University of Houston, 4800 Calhoun Rd, Houston, TX 77204, USA
³ Department of Electrical Engineering, University of California, Engineering Bldg. Unit 2, Riverside, CA 92521, USA

E-mail

pagomez@ee.ucr.edu dlitvinov@uh.edu.edu khizroev@ucr.edu

Journal

Journal of Physics D: Applied Physics Create an alert RSS this journal

Issue

Volume 40, Number 15

Citation

P Gomez et al 2007 J. Phys. D: Appl. Phys. 40 4396

doi: 10.1088/0022-3727/40/15/002

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Abstract

This paper presents a systematic method to design and calculate tunnelling magneto-resistance (TMR) sensors with high signal-to-noise ratio (SNR). The sensing module consists of four TMR devices arranged in a Wheatstone-bridge configuration. Closed-form equations were obtained to calculate TMR sensor current, array output voltage, magneto-resistance ratio, overall noise (thermal and shot) and SNR for a given bandwidth. Using this technique we were able to maximize the SNR by tuning the many parameters of the TMR devices. Typical SNR values are in excess of 45 dB.

PACS

07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

85.75.Ss Magnetic field sensors using spin polarized transport

Subjects