Title :
An all DC-powered Josephson logic circuit
Author :
Hatano, Yuji ; Nagaishi, Hideyuki ; Yano, Shinichirou ; Nakahara, Kouji ; Yamada, Hiroji ; Kominami, Shinya ; Hirano, Mikio
Author_Institution :
Hitachi Ltd., Tokyo, Japan
fDate :
8/1/1991 12:00:00 AM
Abstract :
A novel DC-powered Josephson circuit is reported. An improved HUFFLE-type DC flip-flop with a parallel resistor, to prevent hang-up, is constructed by combinational circuits as well as sequential circuits. The basic device is a vertical type two-junction interferometer with only three-metal layers. The design rule is 2.5 μm. High junction-current density allows for a wide operating margin even with a low inductance load. Basic circuit function test elements have been completed. The DC flip-flop with excess gate current works as a GHz range VCO (voltage controlled oscillator) for internal clock generation. The speedup junction successfully accelerated the switching speed. The ring-oscillator showed a minimum gate delay of 11.3 ps
Keywords :
Josephson effect; flip-flops; superconducting junction devices; superconducting logic circuits; 11.3 ps; 2.5 micron; DC flip-flop; DC-powered Josephson circuit; GHz range VCO; HUFFLE-type; Josephson logic circuit; combinational circuits; internal clock generation; minimum gate delay; parallel resistor; ring-oscillator; sequential circuits; speedup junction; two-junction interferometer; vertical type; voltage controlled oscillator; Circuit testing; Clocks; Combinational circuits; DC generators; Flip-flops; Inductance; Josephson junctions; Resistors; Sequential circuits; Voltage-controlled oscillators;
Journal_Title :
Solid-State Circuits, IEEE Journal of
