4-bit rapid single-flux-quantum decoder

Author

Kirichenko, A.F. ; Semenov, V.K. ; Kwong, Y.K. ; Nandakumar, V.

Author_Institution

State Univ. of New York, Stony Brook, NY, USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2857

Lastpage

2860

Abstract

We describe the design of a fast single-flux-quantum decoder which can be used, e.g., in fast RAMs, general-purpose microprocessors, and communication channel switches. The core of the circuit is a tree of the single-bit SFQ demultiplexer with toggle (rather than the reset-set) control. Three new RSFQ cells: the demultiplexer, D flip-flop with complementary outputs, and serial XOR with large parameter tolerances (dc bias margins of /spl plusmn/25%, /spl plusmn/26%, and /spl plusmn/27%, respectively) have been developed for the decoder project. We have designed the first 16-bit prototype of the decoder for 1-kA/cm/sup 2/ niobium-trilayer technology and tested it at low frequencies. The circuit was completely operable except for 3 (of 16) output SFQ/DC converters. Simulations show that the circuit should allow data rate in excess of 60 Gbit/s and channel switching time below 20 ps.<>

Keywords

decoding; superconducting logic circuits; 16 bit; 20 ps; 4 bit; 60 Gbit/s; D flip-flop; Nb; RSFQ cells; communication channel switches; fast RAMs; general-purpose microprocessors; niobium-trilayer technology; rapid single-flux-quantum decoder; serial XOR; single-bit SFQ demultiplexer; toggle control; tree decoder; Circuit testing; Communication channels; Communication switching; Communication system control; Decoding; Flip-flops; Frequency; Microprocessors; Prototypes; Switches;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403187

Filename

403187