Highly Sensitive CMOS Magnetoimpedance Sensor Using Miniature Multi-Core Head Based on Amorphous Wire

Author

Uchiyama, Tsuyoshi ; Hamada, Nozomu ; Changmei Cai

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., Nagoya Univ., Nagoya, Japan

Volume

50

Issue

11

fYear

2014

fDate

Nov. 2014

Firstpage

1

Lastpage

4

Abstract

We newly report a highly sensitive CMOS magnetoimpedance (MI) sensor based on a miniature multi-core head (~2 mm²). The miniature head consists of 13 μm diameter amorphous wires and pick-up coils totaling 250 turns. In this paper, the sensitivity and noise level of the prototype sensor is investigated. We showed that the noise floor of the prototype sensor is lower than 100 pT/Hz^1/2 for the frequency range of 20-500 Hz. We estimated the peak-induced voltage at the pick-up coil on the basis of off-diagonal impedance theory. The results obtained in this paper will be useful for designing a highly sensitive MI sensor based on a miniature multi-core head with a CMOS pulse circuit.

Keywords

CMOS integrated circuits; amorphous magnetic materials; coils; electric impedance measurement; magnetic sensors; pick-ups; pulse circuits; wires (electric); CMOS pulse circuit; MI sensor; amorphous wire; frequency 20 Hz to 500 Hz; highly sensitive CMOS magnetoimpedance sensor; miniature multicore head; off-diagonal impedance theory; pick-up coil; size 13 mum; Amorphous magnetic materials; CMOS integrated circuits; Coils; Impedance; Magnetic heads; Magnetometers; Wires; Amorphous wire (a-wire); magnetic sensor; magnetoimpedance (MI) element; miniature head;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2014.2326658

Filename

6971649