Hi Team
I don't find the power dissipation graph for TPS7A90, do we have any available information regarding this?
The datasheet does mention RθJA=56.9(℃/W) though, if to draw the graph, then PDmax =125(℃)/ 56. 9 (℃/W)=2.197 W, with the slope=1/ RθJA =1/56.9 W/℃.
For the case when the power dissipation PD=0.7W, ambient temperature Ta=45℃, the junction temperature would be Tj=Ta + RθJA✕PD=45 + 56.9 X 0.7 = 84.8(℃).
If calculate with the power dissipation graph obtain from above, then the power dissipation would be 1.933W, and therefore the power dissipation margin would be 1-(0.7/1.933) = 64%.
Could you confirm if the calculation above is correct?
Regards
David