The operating characteristics of a compact bubble transfer replicate switch

The characterization of a bubble transfer/replicate switch was performed over the temperature range of -25°C to 70°C at 100 kHz. The two level switch utilizes a new 180° degree multichevron corner adapted to the conventional T-I propagation pattern and allows two-bit separation of minor loops on a major input/output track. The manipulation of the domain is similar to an all-chevron single level switch previously introduced by other workers. In addition to transfer and replication, this switch can perform a third function, annihilation of bubbles in the minor loops. It was found that the switching pulse phase and width for all of these functions are relatively insensitive to temperatures. On the other hand, the pulse amplitude margins are somewhat sensitive to temperature because of the decrease in the domain wall energy with increasing temperature. Replication and annihilation have adequate pulse amplitude tolerance over the entire temperature range. However, for a given pulse amplitude the transfer margin degrades noticeably at the temperature extremes. The propagation margin of the minor loop at -25°, 25°, and 70°C is 16, 17, and 13 Oe, respectively, for a drive field of 45 Oe. With the optimum pulse settings, the annihilation function overlaps the propagation margin completely over this temperature range, At -25°, 25°, and 70°C replicate out has a margin of 13, 15, and 10 Oe; and transfer out has 8, 14, and 9 Oe. All the switching functions have at least 40° phase margins.