Temperature change FIT
The Arrhenius equation is a formula the correlates temperature to the rate of an accelerant (in our case, time to failure). Using the Arrhenius equation, you can estimate temperature related FIT given the qualification and the application temperatures.
For example, if you have a FIT of 16.7 at a reference temperature of 55C, you can predict FIT at application temperature of 75C to be 69.2 with 0.7Ea
Equation
\[\begin{aligned} \mathbf{AF} = \mathbf{exp}\left( \frac{E_a}{k} * \left( \frac{1}{T_{low}} - \frac{1}{T_{high}} \right) \right) \\ \end{aligned} \]
AF - Acceleration factor
Ea - Activation Energy
k - Boltzmann Constant
T - Temperature
Important Limitations on Use of Data
TI provides this data for your convenience. However, there are significant limitations of its usefulness as an indicator of how TI parts (including related software) may perform when used in various applications.
THIS DATA IS PROVIDED "AS IS" WITHOUT ANY EXPRESS OR IMPLIED WARRANTY OF ANY KIND INCLUDING WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT OF INTELLECTUAL PROPERTY, OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL TI OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, LOSS OF INFORMATION) ARISING OUT OF THE USE OF OR INABILITY TO USE THE INFORMATION, EVEN IF TI HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
Your use of this data, and all consequences of such use, is solely your responsibility. You must perform sufficient engineering and additional qualification testing in order to properly evaluate your application and determine whether a candidate TI part is suitable for use in that application.
TI parts are specifically designed and manufactured to be used within the electrical, thermal, mechanical and other parameters set forth in TI's product data sheets. Quality and reliability data provided by TI, such as MTBF and fit rate data, is intended to facilitate an estimate of the part’s performance to spec, based solely on the part’s historical observations. It should not be interpreted that any performance levels reflected in such data can be met if the part is operated outside appropriate conditions or the conditions described. Also, the accuracy of any projection is subject to many factors outside TI’s control or knowledge. Users should carefully assess predictive value in light of additional factors as appropriate.
THIS INFORMATION SHOULD NOT BE USED TO ASSIST IN THE PRACTICE OF "UPRATING" OR "UPSCREENING" PARTS FOR USE IN MILITARY OR OTHER CRITICAL APPLICATIONS. Plastic encapsulated TI semiconductor parts are neither designed nor intended for use in military applications and/or military environments. There are significant limitations of this information as an indicator of how commercial, off-the-shelf (COTS) parts may perform in extraordinary applications or environments, and about the hazards of using COTS parts in such applications. TI strongly believes that parts should never be used outside their specified tolerance levels, since upscreening can lead directly to part or system or failure. TI cannot accept any responsibility for part or system failures that occur due to the misuse of its products. Also, any use of a TI part beyond a limit specified in its official TI data sheet voids all warranty responsibility of TI.
Resale of TI parts with statements different from or beyond the parameters stated by TI for part in official TI data books or data sheets, or without the warnings or instructions provided by TI, voids all express and any implied warranties for the associated TI part, and is an unfair and deceptive business practice.
For additional information, please contact TI customer support.