Integrated magnetometer with a digital output

Author

Matz, H. ; Drung, D. ; Crocoll, E. ; Herwig, R. ; Kramer, Eric ; Neuhaus, M. ; Jutzi, W.

Author_Institution

Inst. fuer Elektrotech. Grundlagen der Inf., Karlsruhe Univ., Germany

Volume

27

Issue

2

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

2979

Lastpage

2982

Abstract

A magnetometer with a 50-mm² pickup coil, a sensor SQUID, a flux transformer, and a 1-b A/D converter were integrated on a single 6×12 mm² silicon chip in the Nb-Nb_xO _y-PbInAu technology. The pickup coil has a single turn with a 25-μm-wide Nb strip. Operated in a flux-locked loop and at a clock frequency of 18.4 MHz, the achieved flux noise and magnetic field sensitivity are 3.5 μΦ₀/√Hz and 8.5 fT/√Hz at 1.5 Hz. With a digital feedback of constant step size a maximum slew rate of 11500 Φ₀/s was measured. Below the maximum slew rate the linearity between input and output was investigated

Keywords

SQUIDs; electric sensing devices; gold alloys; indium alloys; lead alloys; magnetometers; niobium; niobium compounds; A/D converter; Nb-Nb_xO_y-PbInAu technology; clock frequency; constant step size; digital feedback; digital output; flux noise; flux transformer; flux-locked loop; linearity; magnetic field sensitivity; magnetometer; maximum slew rate; pickup coil; sensor SQUID; Clocks; Coils; Frequency; Magnetic field measurement; Magnetic noise; Magnetic sensors; Niobium; SQUID magnetometers; Silicon; Strips;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.133836

Filename

133836