Open AccessImplementation of Interface Circuit for Digital SQUID with Sub-Flux Quantum Feedback Resolution
Author(s) -
Ryo Matsunawa,
Kimio Itagaki,
Itta Oshima,
Yuichi Hasegawa,
Mitsuhide Naruse,
Tohru Taino,
Hiroaki Myoren
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1590/1/012039
Subject(s) - magnetometer , squid , computer science , digital signal processing , electrical engineering , electronic engineering , slew rate , decimation , interface (matter) , rapid single flux quantum , physics , filter (signal processing) , computer hardware , engineering , voltage , magnetic field , ecology , bubble , quantum mechanics , maximum bubble pressure method , parallel computing , biology , josephson effect , superconductivity
Digital SQUIDs with single flux quantum (SFQ) feedback have attracted much attention because of the feasibility of realizing a wide dynamic range and high slew rate for digital magnetometers. To achieve a higher resolution, we studied a digital SQUID with sub-flux quantum feedback. We studied implementation methods for an interface circuit by considering the circuit size, power consumption and signal processing to achieve high-resolution and highspeed operation of the digital SQUID magnetometer. Assuming the decimation filter and the up/down counter implemented on a FPGA board, a 1-bit to 16-bit deserializer with an output frequency of 500 MHz could be used for the interface circuit. The circuit scale was 1940 µ m × 1720 µ m, and the bias current was 302 mA. From the simulation results, a sufficient wide bias margin could be obtained up to 30 GHz.