DocumentCode :
946665
Title :
A three-phase single flux quantum shift register with serial biasing
Author :
Whiteley, S.R. ; Barfknecht, A.T.
Author_Institution :
Conductus Inc., Sunnyvale, CA, USA
Volume :
3
Issue :
1
fYear :
1993
fDate :
3/1/1993 12:00:00 AM
Firstpage :
2649
Lastpage :
2652
Abstract :
A three-phase single-flux-quantum (SFQ) shift register has been designed and tested in niobium technology. Serial biasing provides ultralow power dissipation, while allowing operating rates simulated at tens of gigabits per second. This circuit should be compatible with a YBCO weak-link junction process. The authors describe the circuit and its advantages and disadvantages relative to other shift register circuits. They also describe the design constraints, which serve to illustrate some of the issues in general SFQ logic design. Preliminary experimental results from the niobium version are presented. Although the authors are confident that the design works as predicted by simulations they were not able to demonstrate a level of functionality of the pseudorandom generator commensurate with expectations. They believe that this is due to a combination of the usual factors attendant in SFQ circuit testing, i.e. susceptibility to noise and trapped flux, and to correctable conditions related to the treatment of input/output lines on-chip.<>
Keywords :
shift registers; superconducting junction devices; superconducting logic circuits; NbN process; SFQ circuit testing; SFQ logic design; noise susceptibility; pseudorandom generator; serial biasing; shift register; single flux quantum; three-phase; trapped flux; ultralow power dissipation; weak-link junction process; Capacitance; Circuit simulation; Circuit testing; Clocks; Current measurement; Magnetic flux; Niobium; Power dissipation; Shift registers; Yttrium barium copper oxide;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/77.233972
Filename :
233972
Link To Document :
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