Title :
Superconducting digital circuits with low-Tc and high-Tc materials
Author :
Kang, J.H. ; Przybysz, J.X. ; Miller, D.L. ; Meier, D.L.
Author_Institution :
Westinghouse Sci. & Technol. Center, Pitsburgh, PA, USA
Abstract :
The authors argue that superconducting digital electronics is the future trend for high-speed and low-power applications. Low-T c technology based on stable Nb-AlOx-Nb tunneling junctions has been successful in constructing most of the digital circuit logic elements. A four-stage shift register constructed with latching logic operated up to 4 GHz with a power consumption of about 60 μW per gate. A 12-b analog-digital coverter constructed with a single flux quantum (SFQ) logic showed proper operation with the total power dissipated being only about 100 μW. Fabrication of Josephson tunneling junctions with high-Tc materials has been tougher than with low-Tc materials. However, recently developed very high speed rapid single flux quantum (RSFQ) logic circuits can be applied to weak link type junctions fabricated with YBa2Cu3O7-x films. Simulations of the various circuits with weak link type junctions, e.g., shift registers, analog-digital converters, etc., show fast operation and reasonable margins. Applications of similar concepts can be applied to NbN circuits operating at above 10 K
Keywords :
Josephson effect; analogue-digital conversion; digital integrated circuits; high-temperature superconductors; superconducting integrated circuits; superconducting junction devices; superconducting logic circuits; 100 muW; 12 bit ADC; 4 GHz; 60 muW; A/D convertor; Josephson tunneling junctions; Nb-AlOx-Nb tunneling junctions; NbN circuits; YBa2Cu3O7-x films; analog-digital coverter; digital circuits; four-stage shift register; high-Tc materials; latching logic; logic circuits; low-Tc materials; single quantum flux logic; superconducting digital electronics; weak link type junctions; Analog-digital conversion; Circuit simulation; Digital circuits; Energy consumption; Fabrication; Josephson junctions; Logic circuits; Shift registers; Superconducting logic circuits; Tunneling;
Conference_Titel :
High Speed Semiconductor Devices and Circuits, 1991., Proceedings IEEE/Cornell Conference on Advanced Concepts in
Conference_Location :
Ithaca, NY
Print_ISBN :
0-7803-0491-8
DOI :
10.1109/CORNEL.1991.170047
