I need to ensure that the MDIC resistors do not fail derated power limits. What is the estimated power usage for a 40.2 ohm resistor on MDIC0 and MDIC1?
Thank you for your response. I currently have 0603 resistors in there that are rated for 0.1W max, but I have to derate them to 0.056W. Is this OK, or should my derated max be > 0.1W?
Yes, it is OK. 'Maximum theoretical power' can be calculated as GVDD x GVDD / 40.2. This results in about 80mW for DDR2 and 56mW for DDR3. In fact the peak power dissipation would be less, so no problem with resistor's size.
Those resistors are used during hw calibrations, i.e. relatively short time. Theoretically possible peak power is less than 0.1W, so resistors size 0402 is ok.