Sometimes, customer notice that for certain Vishay film chip resistor part series, there can be different modes of operation listed in the datasheet - standard, power, or precision. How can you know which part you’re getting when you order, and how do you specify the correct device?
The answer is that these different modes all refer to the same resistor. The presented operation modes do not refer to different types of resistors, but actually show examples of different loads, that lead to different film temperatures and different achievable load-life stability (drift) of the resistance value. Due to the drift resistance characteristics of film-type resistance under differences in film temperature, applied electrical load and duration of that load, some specified resistors from Vishay can be used in more than one operation mode in their datasheet: precision mode, standard mode and/or power mode.
For example, when looking at the TNPW e3 series, you can see there are two operation modes in the datasheet for this same part: standard mode and power mode.
A further example is TNPW120620K0BEEA; if this part is under normal operating condition in a typical circuit environment which is not more than 125C film temperature, the drift performance results of the part are <=0.05%@1000h, <0.10%@8000h and <=0.30%@225000h. However, if the application of the resistor is under high power condition, this leads a higher tolerance drift performance. The result is as outlined here.
This means that one single resistor is suitable for two different classes of applications depending on your choice of the operating mode and the permitted power dissipation.