I am designing an isolated DC-DC converter with an input of 12V and an output of 5V@12A, at the moment, a flyback seems like the best option. I have read several books regarding the subject and I am proceeding to the implementation; however, I haven't been able to find a transformer that meets my requirements (I have searched on Mouser, Digikey and Newark to no avail). I suppose I've been searching incorrectly, since most of the transformers I have found can only manage up to 2A. I currently have no limitation regarding frequency or turns, but I would like to find the perfect match. So, where can I get the transformer I need? (Do have in mind that I require a website that can ship to Mexico)
Sourcing a transformer a major challenge/headache during the design of an isolated power supply. The more power is required, the harder it is to find an off-the-shelf magnetic. Majority of the power supply transformers are batch-built.
Usually magnetics manufacturers' web sites have better search/filtering tools than distributors like DigiKey and Mouser. Here are my go-to places for shopping for off-the-shelf magnetics:
Lead times may be long too.
Another option is to wind your own, if you only need one or a handful.
Would it make it easier if you designed a flyback for an output of 12V dc and incorporated a buck convertor following producing the 5V. With a 12V DC output, the primary and secondary turns are more evenly matched and easier to source.
In fact, if cost permits virtually any output voltage up to 30V dc would suit as an input voltage to a hell of a lot of post-transformer buck regulators.