I'm trying to calculate power dissipation in a complex load. I know that the power loss due to the resistive component is dissipated, and that the power loss due to the reactive component is canceled out due to an equal amount of power being generated at the load and sent back. My question is how does the op amp handle this, is the power dissipation of the op amp equal to P_resistive+P_reactive? How would I interpret this on an oscilloscope?

EDIT: I should clarify, when I ask how this affects the op amp power dissipation, I really mean how does this affect the junction temperature.

• No. If it was supplying 1V and 10mA to the load and powered by 15V, it would drop 14V at that 10mA current. Your best bet is to measure supply currents, multiply by supply voltages (for + and - rails separately, and subtract power delivered to load. Oct 16 '20 at 22:09
• See if this helps, it's related. Oct 17 '20 at 11:34

It's the same for a lossy power transmission line feeding a resistive/reactive load. The generator at the sending end only produces the resistive power required but the cable wiring resistance losses means that the cable dissipates power based on current flow ($$\I^2R\$$ losses) and that current flow is both reactive and resistive if the load is reactive and resistive.