Design and fabrication of an adder circuit in the extended phase-mode logic

Author

Onomi, T. ; Yamashita, T. ; Mizugaki, Y. ; Nakajima, K.

Author_Institution

Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3172

Lastpage

3175

Abstract

We present the design and the fabrication of an adder circuit in the extended phase-mode logic family. The phase-mode logic is a single flux quantum (SFQ) logic which utilizes an SFQ as an information bit carrier. The single-bit adder circuit is made up of an INHIBIT gate which is the basic device of the phase-mode logic. The circuit has been designed and fabricated using Nb/AlO/sub x//Nb Josephson junctions with Josephson critical current density of 1.0 kA/cm/sup 2/. In order to confirm the circuit operation, the fabricated adder circuit has been tested at low speed. For investigating the possibility of a high-frequency operation, dc voltages generated by fluxon pulse trains have been measured. From the Josephson voltage-frequency relation, the result shows that the circuit has potential to complete the carry operation within 20 psec.

Keywords

adders; superconducting logic circuits; 20 ps; INHIBIT gate; Nb-AlO-Nb; Nb/AlO/sub x//Nb Josephson junction; adder circuit; carry operation; critical current density; design; extended phase-mode logic; fabrication; high-frequency operation; low speed testing; single flux quantum logic; Adders; Circuit testing; Fabrication; Josephson junctions; Logic circuits; Logic design; Logic devices; Niobium; Pulse measurements; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622004

Filename

622004