An avionics guide to uprating of electronic parts

Avionics applications generally require parts that operate reliably in temperature ranges much wider than the commercial 0-70/spl deg/C ranges. However, the availability of electronic parts rated for operating temperature ranges wider than 0-70/spl deg/C is decreasing, as semiconductor manufacturers gradually abandon the nonprofitable military markets and their wide operating temperature range parts. The focus of the semiconductor manufacturers is largely on commercial applications e.g., computers, audiovisual equipment, and cellular phones. One way of meeting this availability problem for parts is "uprating." Uprating is a process to assess the ability of a part to meet the functionality and performance requirements of the applications in which the part is used outside the manufacturers' specification range. An Avionics Working Group and the CALCE Electronic Products and Systems Consortium at the University of Maryland has developed a guidebook consisting of methods for uprating electronic parts. This article presents an overview of these methods including definitions and descriptions.