Laminated ferrite memory

Abstract

This paper describes a random access magnetic memory consisting of a monolithic sheet of ferrite with embedded conductors made by a simple batch fabrication technique: lamination of ferrites. Its tightly packed elements with closed flux paths of only two to three mils in equivalent diameters are the smallest yet realized by any technique. This smallness is being exploited for high speed. Cycle times as short as 100 nanoseconds have been demonstrated. The smallness of the elements leading to modest drive requirements of only a few tens of milliamperes combined with the inherently low cost "integrated" batch fabrication technique opens the possibility of low cost memories of very large capacities: tens or hundreds of millions of bits. A significant cost reduction for the whole memory system is possible because this type of "integrated" magnetic structure lends itself particularly well to be integrated with integrated semiconductor driving and sensing circuits.