MTBF and power supply reliability

Focus:

A brief introduction to the topic of MTBF (mean time between failures) as it relates to power supply reliability. Terms such as MTBF, MTTF (mean time to failure), reliability, and failure rate are defined; the relationship between these terms is defined; and the bathtub curve is explained. Two popular methods for calculating predicted reliability --MIL-STD 217 and Telcordia's SR-332-are discussed. For MIL-STD 217, parts stress analysis prediction and parts count prediction are explained. Concepts such as ground benign, ground fixed, and ground mobile are introduced to explain the influence of environmental factors on MTBF calculations. The article also discusses factors to consider when comparing MTBF ratings from different vendors, electrolytic capacitors as the limiting factor in the useful life of power supplies, and the use of redundancy to address useful life and improve MTBF.

What you’ll learn:

• How to understand the meaning of power supply MTBF ratings
• How to understand methods used by Mil-Std-217 to predict power supply reliability

View the Source

Author & Publication:

John Benatti, Astrodyne, Mansfield, MA, http://www.astrodyne.com, Electronic Products, Aug 01 2009

This article summary appears
in the HOW2POWER Design Guide.

The Design Guide offers
organized access to
hundreds of articles
on dozens of power conversion
and power management topics.

The Design Guide search results
include exclusive summaries
and accurate "how to" analysis
to help you make faster,
more informed decisions.

Search
for more articles