Hi!
I’m actually working on my first home made module. It’s a Ethernet PoE shield for Arduino pro mini (I needed to shrink down my Uno prototype and since I could’t find any mini shields with PoE I decided to make my own).
But since this is my first try I want to know if I am doing things right. this is why I'm asking for your precious feedbacks.
Since Magjack connectors are black magic to me, I'm using a HY931147C connector since this is the same that Arduino CC used on they shield. As I understand, I can use this module for Passive and active PoE application since Pin 4, 5, 7 and 8 are rectified and exposed on v+ and v-. The module also expose RXCT and TXCT but I'll not use them since the PoE module that I'm using will not works If I use both power options and I wanted my module to be compatible with passive PoE with inexpensive injectors.
Link to PoE module :
https://www.arduino.cc/en/uploads/Main/PoE-datasheet.pdfLink to RJ45 connector :
http://www.knap.at/datenblaetter/ste/ste_han_hy931147c.pdfI’m using a W5100 chip. I followed they « reference schematic » but In another document (Layout guide) they say things contradictory to the first document. For instance : in the reference schematic they use 3 different Ground (Chassis completely isolated, Digital ground and analog ground) and in the layout guide they said « It’s better that do not try to partition ground ».
Link to the W5100 hardware design guide :http://www.wiznet.io/wp-content/uploads/wiznethome/Chip/W5100/Hardware/w5100_hardware.zip
So before I’m starting the PCB design, can somebody told me if I’m doing something horribly wrong?
Do I need to replace all analog ground reference with digital ground ? Do I need to keep the RJ45 shield isolated? If yes : How to I draw my isolation area? (In the layout guide the RJ54 is separated from the magnetics, but my connector has integrated magnetics so how can I do that ?)
Thanks a lot everyone !
Edit:
Since the AG9000-S series is really hard to find I've changed my PoE module for a PEM1203 that use the same footprint but a slightly different configuration. It's also possible to use this module with both Mode A and B PoE so I hope I've wired up correctly RXCT and TXCT with the module.
Edit 2: I forgot the bypass caps...