Hello Expert:
Currently we are working with customer to working thermal evaluation ,
can you share How to calculate the parts power consumption example ?
thank you
Hi Roy,
Let me copy the information I emailed you earlier today before seeing this post. 
This would best be estimated using P = IV. The straightforward part is the V – it’s just the supply voltage VSUP, since the current mostly runs to GND.
The harder thing to estimate is the current consumption. This has a couple of different values:
You can estimate by doing a time-weighted average of how much time the device spends in each of these states. For example, let’s say the device is in Normal mode, and you estimate the bus is dominant 20% of the time, and recessive 80% of the time. Then, ISUP would effectively be (0.2)(1 mA) + (0.8)(300 μA) ≈ 440 μA. You can multiply this by VSUP to estimate power dissipation P.
From this, you can use the thermal characteristics of the device to estimate, simulate, or calculate the temperature rise in the device.
Best,
Danny
