Hi Team,
My customer uses UCC27524 without any top side heat sink, is it applicable to estimate the junction temperature simply by Tcase + Power Loss(W)* ΨJT ?
In my customer's case, the power dissipation from IC itself is quite small, but the top side temperature is quite high due to the high ambient temperature(not sure where the heat comes from), how to take ambient into account when calculating Tj?
Regards,
Charles
Hi Charles.
Have you read this document? ψJT is often used like you describe, but given the circumstances, it may actually be easier to just use RθJA. Over a long enough period, the junction should match the ambient temperature, and you can use RθJA as a rough estimate to add the extra heat from power dissipation. Because it is small, I think the error should be small also.
I know the document advises against it, but in this circumstance I think it should give a workable estimate.
Thanks,
Alex M.
