The datasheet for the LM5118 shows a calculation for boost ratio based on maximum duty cycle (which is based on the minimum off time and the switching frequency), but I am not successfully getting it to operate anywhere close to that ratio. It seems that factors such as source resistance (which would affect actual input voltage at the circuit as well as maximum inductor current) and output current also play a part in determining maximum boost ratio. I'm trying to crunch the numbers but am having trouble wrapping my head around it.
Is there any sort of characterization/calculations regarding the effect of output current, source resistance, etc. on the ability of the circuit to achieve the specified boost ratio?
Thanks.