I have some limited amateur-level electronics experience, but I'd like to try something new to me. I'm trying to design a small PCB that among some other fairly simple components will house a DC-DC step-down converter. I have tried to familiarize myself with the topic, and I understand that there are some precautions to take when designing the PCB. My main issue at the moment is - how do I actually select the chip to use? There are hundreds of different chips out there by various manufacturers, all with nice-looking data sheets, and besides some obvious criteria to rule out certain models (not enough current) - how should I narrow down the selection?
These are my requirements:
- convert 12-14 V down to 5 V, no step-up capabilities required
- current 1 A or more
- as few external components required as possible (PCB space is limited by external requirements)
- SOT or other SMD form factor that can be hand-soldered
- should be easily obtainable in smaller batches (10-20 units or so) by a hobbyist in central Europe
- does not require "exotic" external components
- pricing << 1 € per unit
I'm seeing a lot of pre-assembled modules, but I'd rather not use these - a) they are 10x as expensive, b) they take up too much space and c) there's no chance for me to learn anything new when using them...
What other factors do I have to consider when selecting a component? What is the best approach to narrow down the - to me - overwhelming set of components available?