Other Parts Discussed in Thread: UCC21732
Hi Team,
I have question about the safety input.
What's the Ps means and how to deal with this specification?
According to the datasheet, the Ps is 1220mW maximum. but if I calcluate the value, the result should be as below.
68.3(℃/W)*1.22(W) = 83.33℃ ≠ 125℃(150℃ - 25℃)
it seems like that the specification has too margin. I want to understand how to design the thermal related.
Could you also tell me the differences between the Rthja and Figure 3 which is thermal derating curve for limiting power per VDE?
when I calculated the thermal resistance using the figure 3, the calclation result should be as below.
(150-25)℃/1.22W = 102℃/W
I think it's also gap between it and Rthja=68.3C/W. we want to know how to use the figure 3.
Regards,
Masa
