CMOS magnetic field to frequency converter

Author

Chen, Shr-Lung ; Kuo, Chien-Hung ; Liu, Shen-Iuan

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan

Volume

3

Issue

2

fYear

2003

fDate

4/1/2003 12:00:00 AM

Firstpage

241

Lastpage

245

Abstract

In this paper, a CMOS magnetic field to frequency converter with high resolution is presented. It is composed of two voltage-controlled ring oscillators whose output frequency differences linearly vary with the magnetic field perpendicular to the chip surface. The prototype circuit has been fabricated in a 0.5-μm CMOS process and operated at a 5-V supply voltage. The measured sensitivity is 24 kHz/mT and the power consumption is 5.1 mW. The small equivalent resolution of at least 20 μT can be achieved. The frequency offset is 42 kHz when no magnetic field applied. Its nonlinearity within ±120 mT is smaller than 0.56%.

Keywords

CMOS integrated circuits; convertors; magnetic field measurement; magnetic sensors; sensitivity; 0.5 micron; 20 muT; 5 V; 5.1 mW; CMOS magnetic field to frequency converter; MAGFET; high resolution; magnetic MOSFET; magnetically controlled oscillator; magnetooperational amplifier; sensitivity; voltage-controlled ring oscillators; CMOS process; Circuits; Frequency conversion; Magnetic field measurement; Magnetic fields; Power measurement; Prototypes; Ring oscillators; Voltage; Voltage-controlled oscillators;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2002.807485

Filename

1202949