# The meaning of peak efficiency for boost converter

I found the definition of peak efficiency:

Peak efficiency=$\frac{P_{out,max}}{P_{in,max}}$,at first,i thought if i have higher peak efficiency,and i have the output voltage,which is much higher than input.For example,if the peak efficiency of A and B are 30% and 85%,and both inputs are 1V,so the output A should be smaller than output B

But i compare the value with two paper:

A:peak efficiency:73% ; input:50mV ;output:1.2V

B:peak efficiency:85% ; input:0.6V ;output:0.9V

So now i am confused that what is the meaning of peak efficiency,for a boost converter,if its efficiency is higher than the other,what does it mean? this boost conversion is better? this boost has less power consumption?

• You have to read specs carefully : "peak" efficiency is measured at the most favourable working point for the convertor. What matters is the efficiency under the conditions where you are using it. So if A is 73% efficient under your input and output voltages at your load current, and B is 85% efficient at some other condition, don't blindly choose B; check what it does under your actual conditions : it may be less efficient than A in your application. – Brian Drummond Feb 10 '18 at 12:48