---
title: "Connection to transformer"
url: "https://maker.wiznet.io/forum/9624"
markdown_url: "https://maker.wiznet.io/forum/9624/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "kresten"
created: "2013-10-09T09:35:59+09:00"
last_activity: "2017-05-04T08:30:25+09:00"
language: "en"
views: 1069
replies: 4
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Connection to transformer

## Question

Asked by kresten on 2013-10-09 in Ethernet Chips.

Dear wiznet

I am about to make a PCB with the w5500, and in the datasheet there is very limited information about the connection to the transformer. I have a setup like the one in the supplied picture, and my question is, what do i put between the w5500 and the transformer?

Would it be fine with 4 50ohm resistors and 2 0.1µF capacitors and then nothing connecteed to the center taps ?

Thanks in advance!

[![](https://maker.wiznet.io/forum_uploads/wiznet/original/1X/cbb2bd043777ff8a787bd658a4aa54238b53b104.png) 804×663 36.7 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/1X/cbb2bd043777ff8a787bd658a4aa54238b53b104.png)

## Replies

### Reply 1 by hjjeon0608, 2013-10-14

Hi, kresten.

I recommend to make same as our reference schematic.

If you do not, it will not work well.

Best regards.

### Reply 2 by kresten, 2013-10-16

So it is not possible to use a magjack with common center tap ?

### Reply 3 by hjjeon0608, 2013-10-18

Hi, kresten

I recommend to make same as our reference schematic.
Because we do not test other schematics.

Best regards.

### Reply 4 by jameskim, 2013-11-07

Hi kresten,

I attached a reference schematic using a magjack with common center tap.
![](https://maker.wiznet.io/forum_uploads/wiznet/original/1X/d1e3634aaffae4c6938f0bb4e7f90abb5e572fca.jpg)

Frankly speaking, this is not WIZnet’s official reference schematic yet.
I know that they’re testing it internally.

It will work well though WIZnet couldn’t guarantee it officially yet.

Thank you.

javakys

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Source: https://maker.wiznet.io/forum/9624