mean partial power loss

The mean value of the instantaneous power loss in a particular period of the cycle, averaged over the full cycle.

NOTE The term "power dissipation" has been used in the past as a true synonym for "power loss". This is no longer recommended. The term "loss" should refer to the electrical loss (IR drop) at the place of its origin, and the term "dissipation" should refer to the heat that is dissipated from the surface of the device into the environment. Different terms must be provided for the two quantities because, due to internal storage of heat, the two differ with time.

As an exception, "mean power dissipation" may still be used as a synonym for "mean power loss", but only when appropriate, i.e., if the differences with time have no influence on the mean values of the two. This is the case for mean values that are averaged over a cycle. In the latter case, the subscript "(AV)" is usually omitted from the letter symbols.


JESD77-B, 2/00