Specmanship

Abstract:

Specmanship is the art of improving the appearance of technical specifications which, once improved, may no longer reflect reality. For example:

RF Specifications:

Bandwidth is often stated without supplying critical information such as pitch, ground configuration, and dielectric, and is of course reported under ideal conditions.

DC Specifications:

Inductance is shown as self-inductance (which is a mathematical construct), rather than loop inductance which is more representative of reality, but also more dependent upon the environment (pitch, ground configuration, etc.)

Conductance is often shown without describing the conditions: In free air or in plastic? What is the resulting temperature rise?

Mechanical specifications:

Total compliance is shown, rather than the more-useful DUT-side compliance. Force is given without recognizing that precision springs have a tolerance of +/- 20%.

The presentation will provide several examples of specmanship, and also present three examples of test reports that thoroughly explain the origins of several specifications with explanations of the test methods used to derive them – the way specifications should be created and presented to users.

Version: March 2012
Presented by: Jim Brandes
Presented at: BiTS