Phase-Mode Circuits for High-Performance Logic

Takeshi ONOMI  Yoshinao MIZUGAKI  Hideki SATOH  Tsutomu YAMASHITA  Koji NAKAJIMA  

IEICE TRANSACTIONS on Electronics   Vol.E81-C   No.10   pp.1608-1617
Publication Date: 1998/10/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: INVITED PAPER (Special Issue on Low- and High-Temperature Superconductive Electron Devices and Their Applications)
Category: Digital Applications
superconductive electronics,  Josephson junction,  single flux quantum,  logic circuit,  integrated circuit,  

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We present two types of ICF (INHIBIT Controlled by Fluxon) gates as the basic circuits of the phase-mode logic family, and fabricate an adder circuit. The experimental result demonstrates that the carry operation followed up to 99 GHz input pulses. The performance of Josephson devices is improved by the use of junctions with high current density (Jc). We may use the high-Jc junctions without external resistive shunt in the phase-mode logic circuits because of reduction of the junction hysteresis. One of the ways to overcome the large area occupancy for geometric inductance is to utilize the effective inductance of a Josephson junction itself. We investigate a circuit construction with high-Jc inductor junctions, intrinsically overdumped junctions and junction-type resistors for the compactness of circuit integration, and discuss various aspects of the circuit construction.