# TI LM25118 buck boost, variable power supply

For a part of my next project I'm required to make a variable power supply module. I have never designed a power supply and I would like to make my life as easy as possible. Thats why I would use LM25118 buck boost controller. The datasheet is a bit confuseing for me.

The input voltage varies from 3 to 6 volts (can deliver 4A). The output voltage needed is between 2 and 12 volts. The output voltage would be regulated with a potentiometer. I would like to look at the worst possible scenario when I have 3 volts at the input.

1. What voltage do I have to set to still get 1A at the output, while there is a 3 V input?
2. Is there a better solution? Like a controller from another manufacturer something else. I would need at least 1A at 5V out, 1A at 9V out would be great! (with 3V in)

Note that it's not easy to operate a buck-boost supply at $V_\text{in}\approx V_\text{out}$; if that is among your requirements, more involved architectures like Cuk or SEPIC might be better suited.