Hi guys! For my project, i was tasked to do up a justification for a previous engineers design. Upon obtaining the voltage requirements,

i was wondering if i could calculate the power dissipation with regards to the

and therefore calculate the thermal effects determine if it satisfies the board specifications. Can i calculate the output voltage done, instead of the formula, by doing a summation of the power utilised by each component within the circuit?

 

Additionally, I also was looking at his(or her) schematic,(the engineer is not around anymore and left no documents), and i saw he used a 4.7Kohm resistor a his choice for his pull-up resistor for his I/O expander, PCA9557. Utilizing fast mode, the values used for the formula are as shown,



Can i ask if the calculations are correct? or if i am missing something? because from his schematic it seems that the clock lines are connected in such a way and the capacitors in parallel are much bigger than the threshold itself.



Once again, thank you for the advice.

 

bump!