Hello! I just want to clarify some of these points. Saying it is the world's smallest switch is a bold claim, and there are definitely alternative options around. However, our board scales really well. The main reason we say it's the cheapest is because the real BOM is only around 4-5 dollars. Our small run of ~25 boards came out to ~$7 each. If you agree with my interpretation, perhaps the words "smallest and cheapest" can be together?
Magnetics: We have built-in "external" magnetics, so the physical ports don't have the magnetic inductors required in the Ethernet standard. This makes the ports super small, allowing us to use 1.25mm pitch Molex Picoblade connectors. Again, thanks for the suggestions. We're still learning and the team is taking all the comments very seriously.
The "real" BOM is what you can actually get. If you don't have the funding to make 10,000 boards in order to push to cost down to $4, then the BOM is $7.
Given this was made by a high school robotics team and it accepts up to 12V, it's likely that the intended use case is on a robot that already has a 12V battery
Fast Ethernet +/- pins go through a special 1-turn transformer for electrical isolation installed between the PHY and RJ45 connectors, commonly referred to as "the magnetics" in Ethernet world. It's physical ferrite and copper object molded like a chip, therefore it can't be trivially integrated into a silicon or in MCM. Hence most Ethernet chip require one external to the chip, and in this case it is indeed external to the chip, and integrated into the board at the same time.
(yes a cap in-line works too if you know what you're doing)
monoprice #41710 is $10 all in with a price break starting at qty 2.
maybe you want to qualify your description with 'embeddable'.
> built-in magnetics
interesting b/c the website says `external magnetics`