What is the MTBF of the power adapter
Digital electronic products are becoming increasingly ubiquitous, from smartphones and tablets, fitness monitors, and home digital assistants, to internet and telecommunications infrastructure, data centers, transportation management, and fly-by-wire aircraft. As we become more reliant on these products in our daily lives, we see people becoming increasingly aware of issues around the reliability of the electronic components used internally.
Defining reliability and mean time between failures
Given this trend, it is no wonder that design engineers place greater emphasis on reliability during the component selection process, using key data points such as Mean Time Between Failures (MTBF) from component vendors to make design decisions. While MTBF can be a useful indicator for estimating reliability, especially when comparing components from multiple suppliers, the trap that many fall into is mistakenly thinking that the MTBF figure directly equates to the expected lifetime of the component. Given the many misunderstandings surrounding this topic in electronic design, a re-examination of the relationship between the reliability and lifespan of electronic components is crucial.
Reliability is defined as the probability of a single product unit operating normally in a specified time period under specified conditions. It can be represented statistically as:
R(t) = e^-λt
Where λ is the intrinsic failure rate, excluding early failures (infant mortality) and wear-out failures (end of life).
With this information for each component, we must sum the individual failure rates of all components comprising the system to understand how long the entire product will last (λtotal = λ1n1 + λ2n2 + … + λin). Clearly, the reliability of the system will not be better than that of its least reliable component. For designers, focusing on weaker components can pay dividends.
The important point is that while MTBF – although it can form the basis for analyzing and comparing the reliability of products and components – should not be interpreted as a direct expression of expected lifetime.
Now embedded in the fabric of our lives and work structures, the demand for reliability in digital products will continue to grow. As a seasoned professional with over 10 years’ experience in the power industry, we can help engineers enjoy a better product design experience by communicating clearly about the reliability, MTBF, and actual expected lifespan related to our products.
