Title :
Design and demonstration of fundamental logic circuits based on a single-flux-quantum gate with a resettable latch
Author :
Takeuchi, Nobuo ; Akahori, A. ; Mori, N. ; Suzuki, Y. ; Furuta, F. ; Fujimaki, A. ; Hayakawa, H.
Author_Institution :
Dept. of Quantum Eng., Nagoya Univ., Japan
fDate :
3/1/2001 12:00:00 AM
Abstract :
We have confirmed the importance of the tolerance design for obtaining correct operation in larger-scale Single Flux Quantum (SFQ) logic circuit. Experimental results show that the bias margin of SFQ/dc converter is considerably enhanced by employing tolerance design. The primitives of Single-Flux-Quantum-logic with Ressettable Latch (SFQ-RL) are designed to have high tolerance. As a result, relatively complex circuits based on SFQ-RL including 4-bit Shift Register, 3-Input Majority circuits, binary counter operate correctly with sufficient bias margins. These circuits are fabricated in NEC´s standard process using 2.5 kA/cm2 Nb/AlOx/Nb junction technology
Keywords :
counting circuits; flip-flops; logic design; logic gates; majority logic; shift registers; superconducting logic circuits; tolerance analysis; Nb-AlO-Nb; Nb/AlOx/Nb junction technology; SFQ/DC converter; binary counter; logic gate; majority circuit; optimization; resettable latch; shift register; single flux quantum logic circuit; tolerance design; Counting circuits; Critical current; DC-DC power converters; Energy consumption; Large-scale systems; Latches; Logic circuits; Logic design; Niobium; Numerical simulation;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
