Title :
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
fDate :
3/1/1991 12:00:00 AM
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-NbxO 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-NbxOy-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;
Journal_Title :
Magnetics, IEEE Transactions on
