A SQUID Bootstrap Circuit with a Large Parameter Tolerance
ZHANG Guo-Feng1,2,3, ZHANG Yi2,3**, Hans-Joachim Krause2,3, KONG Xiang-Yan1,3, Andreas Offenhäusser2,3, XIE Xiao-Ming1,3
1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences (CAS), Shanghai 200050 2Peter Grünberg Institute (PGI-8), Forschungszentrum Jülich (FZJ), D-52425, Jülich, Germany 3Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai & FZJ, Shanghai 200050
Abstract：The voltage biased (SQUID) bootstrap circuit (SBC) was recently introduced as an effective means to reduce the preamplifier noise contribution. We analyze the tolerances of the SBC noise suppression performance to spreads in SQUID and SBC circuit parameters. It is found that the tolerance to spread mainly caused by the integrated circuit fabrication process could be extended by a one-time adjustable current feedback. A helium-cooled niobium SQUID with a loop inductance of 350 pH is employed to experimentally verify the analysis. From this work, design criteria for fully integrated SBC devices with a high yield can be derived.
2013, Vol. 30 
