Characterization of a 4 Mbit bubble memory device with "Wide gap" permalloy propagation tracks

A 4 Mbit bubble memory device with "wide gap" propagation tracks has been fabricated and characterized. The 4 Mbit device is composed of four 1 Mbit blocks which are architecturally designed to be compatible with an existing 1 Mbit device, and the relaxed function design has been employed to achieve functional compatibility, in addition to architectural compatibility. The results obtained in the characterization of functions, such as a generator, a detector, swap gates and replicate gates, show the realization to guarantee the same operational conditions as those of the 1 Mbit device. The overall operating margins of the fabricated chips were measured in the temperature range of 0°C to 90°C, and the temperature coefficients were found to be -0.18 %/°C to -0.20 %/°C. A compact package for the 4 Mbit chip was designed. The package size is 36.4 × 34 × 11.5 mm³and the number of pin-outs is 42. A sufficient operating margin was confirmed in the case temperature range of -10°C to 90°C. The power consumption of the device is 1.1 W, which is approximately 0.6 to 0.7 times as much as those reported so far.