DocumentCode
516323
Title
A Low Noise CMOS Preamplifier Operating at 4.2 Kelvin
Author
Kleine, U. ; Bieger, J. ; Seifert, H.
Author_Institution
Siemens AG, Corporate Research and Development, ZFE BT ACM 23, Otto-Hahn-Ring 6, 8000 Munich 83
Volume
1
fYear
1993
fDate
22-24 Sept. 1993
Firstpage
134
Lastpage
137
Abstract
A low noise CMOS readout preamplifier operating at liquid helium temperatures for measuring human biomagnetic fields is described. The input of the folded cascode amplifier can be attached directly to a low impedance SQUID output (Superconducting QUantum Interference Device). Despite the occurrence of the kink effect in MOS transistor charcteristics at 4.2 Kelvin, no abnormal operation has been observed. An equivalent noise voltage density of 0.3 nV/¿Hz at 500 kHz has been measured. with such a preamplifier circuit the expensive shielding currently used in diagnosis systems can be simplified drastically.
Keywords
Anthropometry; Biomagnetics; Helium; Humans; Kelvin; Noise measurement; Preamplifiers; SQUIDs; Superconducting device noise; Temperature measurement;
fLanguage
English
Publisher
ieee
Conference_Titel
Solid-State Circuits Conference, 1993. ESSCIRC '93. Nineteenth European
Conference_Location
Sevilla, Spain
Print_ISBN
2-86335-134-X
Type
conf
Filename
5467927
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