Thermoelectric cooler (TEC) is a semiconductor device which is characterized by unique heat pump performance with high efficiency, compactness and durability. The unique ability of TECs to heat and cool, permits them to lower temperature of an object below ambient as well as to stabilize temperature of objects in widely varying ambient conditions.
Here we mention some application tips that can help in optimal use of TECs.
Standard operation temperature of regular TECs is within the range -60...+85°C. TECs can withstand even higher temperatures - close to internal solder melting point (for RMT TECs - it is 230°C). But TEC lifetime decreases gradually with temperature raise.
TEC life time depends on operation temperature, and estimation of the lifetime at given temperature is possible on the basis of Arrenius equation
where t1 and t2 - TEC lifetimes at corresponding operation temperatures T1 and T2;
Ea - energy of activation of TEC failure mechanisms; k - Boltsman Constant.
The plot shows dependence of TEC lifetime on operation temperature in accordance to the above dependence and experience of RMT concerning TEC failure reliability and failure mechanisms.
In table some typical examples of RMT TEC median life (MTBF) are shown depending on temperatures.
|Operation temperature, °C|
|TEC Lifetime, hours||9,9E+05||6,0E+04||2,7E+04||4,6E+03||1,8E+03||3,6E+02|
Note: MTBF (Mean Time Between Failures) - for non-reparable devices, like as TECs, MTBF can be considered as «useful life», meaning average time to failure. If a sample batch of devices N is in operation then MTBF is average lifetime - time to failure of 50% of sample size.