L6920DB temperature range

qwhus · ‎2025-09-02

The L6920DB temperature rating is not specified in the datasheet. However, it gives the temperature data as Max Tj=150C, Thermal resistance is 180C/W. Based on Tj=Ta+Pd*ThetaJa, if Ta=85C, then the Pd allowed in this temperature is very low. Is L6920DB rated temperature range specified as -45C to 85C?

Peter BENSCH · ‎2025-09-05

You should ask the question the other way round, as the data sheet is always the exclusive source for guaranteed functionality. The information in the eStore, on the other hand, may have been entered incorrectly. However, I would also like to point out that the L6920DB was launched on the market back in 2006, the last data sheet change is just as old, and further changes are very unlikely.

As already discussed, it is theoretically possible that the temperature could rise above 85°C under maximum load. As long as you ensure that the maximum junction temperature is not exceeded, the device will continue to function.

Regards
/Peter

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Peter BENSCH · ‎2025-09-02

Welcome @qwhus, to the community!

There is in fact no specification for a specific temperature range, but, as you have correctly recognised, only the maximum junction temperature. Significant power loss generally only occurs at high peak currents. As a developer, you therefore have control over the maximum temperature up to which the device can be used.

Hope that helps?

Regards
/Peter

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qwhus · ‎2025-09-03

Hi, Peter

Thanks for your reply. From the "order part" webpage, https://estore.st.com/en/products/power-management/dc-dc-switching-converters/boost-regulators/l6920db.html, it lists the max and min operating Temp as -40C to 85C, my question is why this specification is not listed on the datasheet?

Peter BENSCH · ‎2025-09-05

You should ask the question the other way round, as the data sheet is always the exclusive source for guaranteed functionality. The information in the eStore, on the other hand, may have been entered incorrectly. However, I would also like to point out that the L6920DB was launched on the market back in 2006, the last data sheet change is just as old, and further changes are very unlikely.

As already discussed, it is theoretically possible that the temperature could rise above 85°C under maximum load. As long as you ensure that the maximum junction temperature is not exceeded, the device will continue to function.

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

qwhus · ‎2025-09-05

Hi, Peter

Not only one place ( https://www.st.com/en/power-management/l6920db.html#quality-reliability) specifies the L6920DB is industry rated, you can't blame the data was entered incorrectly. To be straight, do you have the test data of the Reference Voltage range at low temperature (-25c or -45C) of this device? The datasheet shows it is from 1.18 v to 1.27v at 25C, we want to know the range in low temperature. Thanks

Peter BENSCH · ‎2025-09-05

All available specifications are contained in the data sheet. Conversely, what is not in the data sheet is neither specified nor guaranteed.

Regards
/Peter

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