The first consideration is the scope of the ratings that design engineers must meet in their applications. These span from about 1/3 horsepower for applications such as a refrigerator, to more than 10 HP for industrial HVAC. Many residential applications can be satisfied with 600V rated devices. However, some commercial and industrial applications operate on 460 VAC and therefore require 1200 V rated devices. Next are the design objectives. A high level of integrated functions is appreciated by engineers pressured by short design cycles, limited space on printed circuit boards, and the need for improved manufacturability. Easy access to accurate temperature data is necessary to make system control decisions. To have confidence in device selection requires eliminating possible variables and failure modes. Finally, engineers are constantly under pressure to improve system performance and reduce costs. However, it is difficult to make significant and frequent design changes. Ideally, they would be able to implement improvements with minimal disruption to the overall design.