A Power-over-Ethernet Dock for the Onion Omega board
This is a KiCad circut board design for an Onion Omega "dock" that connects the Onion via Ethernet, while also powering it via 802.3af Power-over-Ethernet.
The Onion Omega is a cheap ($10.75) linux single-board computer, and supports WiFi and Ethernet. For more information on the Onion Omega, see the Onion Omega site.
This board is designed to be as small as possible while still providing an isolated 15-watt PoE supply. The 48 VDC power from PoE is converted into 12 V using a TI LM5070 in a flyback configuration. The 12 V is further stepped down to 5 V and 3.3 V using two TPS62135x DC-DC buck converters. 12 V was chosen to allow running 12V perhierals off of the board, such as 12V LED lighing strips.
Four prototype boards have been built, and they work. There are some issues to work out and fixes to commit, but here's the v1 board run:
