Operation of the Cryogenic Continuous Film Memory Cell

Problems and requirements associated with using the cryogenic continuous film memory (CCFM) cell in a random access memory with coincident current cell selection are discussed. Pulse measurement techniques are described which provide information on the storage level within the cell and on the basis of several simple assumptions, permit the operating range (drive current tolerance) of the cell in a memory array to be calculated. The influence of nonideal superconducting to normal phase transitions on storage levels is discussed as is the effect of various memory disturb programs on cell operation. The restricted operating limits of the CCFM cell are found to place requirements on cell uniformity which severely tax today's thin film capabilities. Copyright © 1964 by The Institute of Electrical and Electronics Engineers, Inc.