A PPLICATION
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课程总结怎么写eupec GmbH + Co KG Max-Planck-Straße 5D-59581 Warstein Tel. +49(0)2902 764-0Fax +49(0)2902 764-1256EMail
男哑铃
An Infineon Technologies Company Definition of FIT and MTBF
A failure rate λ=is defined by the number of failures r during a specific test time t of n components:
吴道子The unit for failure rates is 1 fit (f ailures i n t ime) = 1*10-9h -1,meaning one failure in 109 operation hours of the device.
搜下留情
A component specified with 100 fit is therefore expected to operate 107 hours.
Example: Testing 4000 components for 5000 hours with 2 failures in this time leads to a failure rate of
The failure rate or fit value is ud to calculate the MTBF (m ean t ime b etween f ailures) of a complete equipment existing of i parate components with individual failure rates λi :MTBF = 1 / Σ λi
Example: An equipment is built of 50 components with 250 fit each, which adds up to a MTBF of 1 / (50×250fit) = 80.000 h. The equipment is operated 18 hours a day and 300 days a year under the specified operating conditions. The expected lifetime is therefore: 80.000 h / (300*18 h) = 14.8 years.t n r
⋅=λfit fit h h h热高乐园
10010101015000*40002197
1
7==⋅==−−−−−λ or expresd in fit:
喝中药可以吃虾吗F
明朝张居正
IT-R ATES FOR IGBT M ODULES Page 2 of 2
日历记事Together with the fit value, the operating conditions must be given. For eupec IGBT modules the conditions are: operation at 50% nominal voltage, 50% nominal current and Tamb = 40°C.Tracing back shipped modules, estimated accumulated operation hours and field returns for the last years, we could calculate the following tendency in the failure rates:
