COMPONENT SELECTION FOR USE BEYOND MANUFACTURERS’ TEMPERATURE SPECIFICATION

Abstract

Products in many industries need electronic parts that can operate over wide temperature ranges. Electronic parts may not consistently be rated to meet the application requirements. The uprating process was developed in the late 1990s as a possible method to address this problem. 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 manufacturer’s specification range. Uprating is built into the performance assessment step as part of the part selection and management process and requires validation through electrical testing. This process can be resource-intensive in terms of time and money, and it is becoming increasingly so with the increase in part complexity. Therefore, there is a need to preselect parts that have the potential to be uprated. This thesis developed an uprateability assessment process to facilitate this pre-selection. This process depends on the thermal information provided in recommended operating conditions and absolute maximum ratings.In this thesis, a quantitative analysis of 140 datasheets is performed to identify the trends in published thermal information for absolute maximum ratings, recommended operating conditions, assembly information, thermal resistances, and temperature dependence of electrical parameters. The analysis identifies the best practices, inconsistencies, and incompleteness in the information provided by the manufacturers. This thesis provides a methodology to establish recommended operating conditions and absolute maximum ratings when unavailable in the datasheets. It outlines the criteria necessary to verify a comprehensive rating section, assigning an information availability level to the thermal ratings to assess the quality of the information provided by the manufacturer, and recommends sources to obtain the missing information. This thesis also provides an uprateability assessment methodology to identify the components that have the potential to be uprated out of an initial pool of components. The goal is not to uprate all components under consideration but to identify the potential ones that are likely to succeed before they are experimentally evaluated. This process evaluates and eliminates the parts that cannot be uprated, narrowing the potential candidates for uprating and reducing experimental costs.