Hi I'm currently making this stepwise charging circuit using ADG712 on LTSpice and I want to find the overall power efficiency of this circuit (ignore V7, V8, V9, V10, V13, V14 because I will be using a microcontroller for that anyways). I have tried using the .meas command and using different parameters but I kept getting unreasonable efficiency values (either below 1 or above 100). I'm really stuck on this so any help will be great



The red plot is the power at the load capacitor and the blue plot is the power at the input (V6, the diode is there to limit the current). I also tried checking the power at +V (voltage supply to power up device) and it is 0. The light blue plot is just the red plot divided by the blue plot.


These are some of the outputs of the measure command that I tried:

pin: AVG(v(n003)*i(v6))=-0.0294539 FROM 0 TO 4.99999e-06
pout: AVG(v(n001)*i(c4))=8.86914e-05 FROM 0 TO 4.99999e-06
eff: (pout/pin)*100=-0.30112

pin: AVG(v(n003)*abs(i(v6)))=0.0293472 FROM 0 TO 4.99999e-06
pout: AVG(v(n001)*abs(i(c4)))=0.0317144 FROM 0 TO 4.99999e-06
eff: (pout/pin)*100=108.066

Which looks very odd. Is there a specific way for me to calculate the efficiency for a complex power waveform or am I missing something here.

 

Do a Ctrl-LeftClick on the plotted power waveform title.
That will give a window with the energy and average power over the displayed waveform time (example below):

 

Do a Ctrl-LeftClick on the plotted power waveform title.
That will give a window with the energy and average power over the displayed waveform time (example below):

View attachment 335717

Okay thank you.