Dear Customer:

Aeroflex UTMC Microelectronic Systems Inc. (UTMC) appreciates your interest and use of our products, specifically the UT1553B Remote Terminal Multi-Protocol (RTMP). The purpose of this letter is to inform you that UTMC intends to migrate the RTMP (Standard Military Drawing (SMD) #5962-88645) to a new wafer fabrication facility. The supply of current wafer material will soon be at a level that necessitates this migration.

The new version of the RTMP remote terminal interface is designed to be a direct package replacement for the existing RTMP. This new version will also be a fit-formfunction replacement and demonstrate the same electrical characteristics as the current version.

Aeroflex UTMC has sufficient die inventory to yield approximately 2,200 finished good units (die code UN05). The inventory of the existing RTMP is being offered to customers until the replacement product is fully qualified. Aeroflex UTMC plans to cease shipping product built from the old mask set, once qualification of the migrated version is complete. We expect to use the same SMD number (5962-88645) for the new material.

An updated version of the RTMP Data Sheet will be made available on the UTMC website (www.utmc.com) by the end of the second quarter 2002. For reference, attached is a current listing of RTMP part types and SMD numbers. If you have any questions please contact me at (719) 594-8252.