Analog/digital converter

Abstract

Abstract PURPOSE:To realize a very high speed operation with a simple construction by a method wherein a converting part composed of a plurality of superconducting current paths which are connected in series and whose respective critical current conditions are so predetermined as to be different from each other with a certain difference and a means to detect the cut-off of a superconducting current are provided and the change of the current which is applied to the converting part and to which an analog signal is superposed is outputted. CONSTITUTION:A converting part is composed of superconducting members S1, S2...Si...Sn+1 which are piled and whose sectional areas are varied step by step. Thin insulating layers are provided in junction parts between the respective superconducting members and Josephson junctions J1, J2...Jn whose respective critical currents are different from each other are formed. Terminals P2, P3...Pn for voltage detection are connected to the respective superconducting members S2, S3...Si...Sn. A predetermined current I0 which is smaller than the critical current of the Josephson junction J1 which has the minimum critical current condition is applied. When the input current is increased by the superposition of an analog signal the superconducting conditions of a certain junction Ji and of junctions which have lower critical current conditions than the junction Ji are broken and electric resistances are produced. Thus, a voltage corresponding to the change of an environmental magnetic field is inputted to an encoder to obtain a digital binary signal.

Inventors

• 👤 Nobuo Shiga

Bibliographic Details