Hello team,
My customer is designing board with TMP117.
They want to place vias for accurate measurement.
What is the recommended diameter and numbers of the vias?
Best Regards,
Kei Kuwahara
Hi Kei,
There are 2 app notes that may be useful here: "How to monitor board temperature <https://www.ti.com/lit/ab/snoaa26/snoaa26.pdf> and "PCB guidelines for surface mount devices" <https://www.ti.com/lit/an/snoa967a/snoa967a.pdf>.
A designer can use as many parallel vias or filled conductive vias as feasible to transfer heat from the heat source to the temperature monitor to create a fast thermal equilibrium between the two objects. The recommended size and number of vias may depend on the desired thermal response and PCB design restrictions.
Section 1.3.5 of the second app note details how to calculate the thermal conduction path of a via, which can be used to determine if a regular via suffices, a larger size or quantity of vias is required, or if vias need to be filled with a conductive fill.
Best regards,
Sakeenah Khan
