Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

PoE circuit question

Status
Not open for further replies.

I14R10

Full Member level 3
Joined
May 31, 2015
Messages
185
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
2,750
I'm trying to implement a power over ethernet for my circuit, it's a simple w5500 web server that I want to power. I checked the w5500 recommended schematics on their web site. The problem is, they don't have the recommended schematic for PoE circuit. And for the last few weeks that I've been reading about it, there's very few real circuit schematics that shows how it's done properly. W5500 recommended circuit with external magnetics look like this

1679922225223.png



and my circuit looks like this

1679922172758.png


The only difference in my circuit is those 75R resistors that I used instead of three 49.9R. But that seems wrong to me. PoE sends up to 48V DC and those 48V would appear on the magnetics center taps (pin 10 and 15 on U4) (going through R32/R33 and R17/R18). If I understand correctly those resistors and capacitor C22 is there to supress some voltage spikes or EMI. Would the circuit work fine if I just disconnect the R32/R33?
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top