Magnetic bubble logic component library

A comprehensive library of magnetic bubble logic components has been established, with emphasis on standardization in terms of dimensions and I/O to facilitate VLSI chip composition. These components were designed in a current-access perforated-sheet configuration and fabricated on magnetic garnet wafers supporting 2-µm bubbles. The operating margin for each component was studied individually on 8-µm period devices at 1 MHZ by using a high-speed magneto-optical sampling-camera system. The bubble-to-bubble interaction force was found to be very reliable in producing successful logic operation with a 12-percent bias-field margin for the XOR/AND gate equal to 80 percent of the bubble-propagation margin and about 60 percent of the free-bubble bias-field margin. The experimental results show 10.8, 10.7, 10.2, 10, 10.6, 8.5, 12, 8.5, 15, and 9.5-percent bias-field margins for the SWITCH, AND/OR, COMPARATOR, SEARCH, LATCH, BIT-PAIR SEPARATOR, MERGER, CROSSOVER, ANNIHILATOR, and SPLITTER gates, respectively. An 8.5-percent overlapped bias margin has been obtained for all of the logic components. Transient pictures taken with a small incremented delay revealed that the bubble motion in perforated-sheet logic devices is uniform both in the velocity excursion and shape distortion. The behavior of various components at different values of the bias field and drive current is all qualitatively interpretable on the basis of experimental observations. The feasibility of these logic components is successfully demonstrated.