# Boost converter efficiency

I simulated a boost converter on LTspice and have measured the steady-state output power to be 80.49 W and the average power drawn out of the input source during steady-state operation of the converter to be 84.7W. Yet when I calculate the efficiency, $$\P_{out}/P_{in}\$$, I get 0.95, which seems to be incorrect according to a Coursera homework assignment.

Am I missing something? Does the average power consumption of the gate driver matter?

• Those figures look plausible, if quite good (quite near to 1.00). What's the actual problem? Nov 27 '19 at 21:06
• Did you mean "watts" instead of "volts?"
– JRE
Nov 27 '19 at 21:09
• @Neil_UK the converter efficiency I am inputting is being marked as incorrect, so I am wondering if the gate driver power consumption has a role in this. Nov 27 '19 at 21:09
• @JRE yes thanks for catching that Nov 27 '19 at 21:10
• The input power should include the power used by the gate driver. The math is trivial, and correct. That leaves the question of how accurate (or correct) the power measurements are.
– JRE
Nov 27 '19 at 21:13

The efficiency of the boost converter is $$\P_{out}/P_{in}. P_{in} \$$ is a sum of the average power drawn out of the input source during steady-state operation of the converter and the power used by the gate driver. $$\P_{out}/P_{in} = 80.49 W/(84.7 W + 0.205 W) = 0.948 W/W \$$ to be exact.