What are the differences between MTBF and Lifetime?
A: There is a certain degree of confusion when it comes to the MTBF and Lifetimes of power supplies. The Mean Time Between Failure (MTBF) of a unit is the statistical approximation of the cumulative hours a number of units can be expected to operate before a failure occurs. For example, if 10,000 units operated in the field 10,000 hours with an MTBF of 1,000,000 hours, 10 failures would be expected (failure rate = (10,000 x 1,000) / 1,000,000)). The MTBF is not the length of time a supply can be expected to operate without failure.
The lifetime of a power supply is the period of time expected between starting the supply and the beginning of its wear-out phase. This is calculated by determining the life expectancy of each component of the supply is finding the component with the shortest lifespan, or the weakest link. The life expectancy of this component determines the life expectancy of the supply itself. In power supplies, the weakest link is usually the electrolytic capacitors. Ottima uses long life capacitors in order to maximise the life expectancy of our supplies.