# DC-DC Converter Datasheet - What does “Temperature Coefficient” Refer to?

I am trying to understand all aspects of DC-DC converter datasheets. One thing I am unsure of is what is referred to as "Temperature Coefficient." An example of this can be seen in the "Output" section of this datasheet.

I am thinking it may refer to efficiency? So the rated efficiency drops 0.03% per degree Celsius of temperature rise? It seems like it should rise more than that.. Or does it perhaps refer to voltage accuracy?

Is there a general rule for this sort of thing across DC-DC converter datasheets, or is it necessary to email the individual company?

• It's simply telling you that the output will change by 0.03% per each 1 degree change in temperature. And the output here is the voltage. – Eugene Sh. Jan 12 '18 at 18:16
• @Eugene: No, it's telling you that the output may change by up to ... – Olin Lathrop Jan 12 '18 at 19:34

Notice that this spec is in the "Output" section, so applies to the output: It tells you how much the output voltage can change as a function of temperature alone. That spec is 0.03%/°C. Seems quite clear.

For example, if you change the temperature of the converter by 30 °C, then the output voltage can change by up to 0.9%. If you started at 12 V, for example, then after 30 °C change, you are only guaranteed to be within 12 V ±0.9% = 12 V ± 110 mV = 11.89 to 12.11 V.

• Thanks, you are right it is clear. I was overthinking it. – scuba Jan 12 '18 at 19:14

The output measurements were taken at a certain operating and ambient condition (predefined load, ambient temperature, etc). The thing is that there is a variation in the output whenever there is a temperature increase or decrease. 0.03%/°C just means that the output varies within 0.03% whenever there is a 1°C change.

If the measurements were taken at 25°C and it is 30°C then you just need to do the math and you will get the expected output.