---
title: "W7500P termination differential pairs"
url: "https://maker.wiznet.io/forum/11704"
markdown_url: "https://maker.wiznet.io/forum/11704/md"
type: "Forum topic"
category: "MCU & Boards"
author: "Jeff"
created: "2016-03-02T12:24:26+09:00"
last_activity: "2017-05-04T08:38:24+09:00"
language: "en"
views: 526
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W7500P termination differential pairs

## Question

Asked by Jeff on 2016-03-02 in MCU & Boards.

Hi,

I have a question about the WIZnet W7500P (with build-in PHY).

I looked at the W7500P reference schematic and the Altium files of the WIZwiki W7500P and i noticed that there are no 50 ohm resistors placed in order to terminate the differential pairs. Are those resistors build into the chip?

Thanks!

## Replies

### Reply 1 by jakubokaj, 2016-03-07

Hello,

From IP101G datasheet:

Using either 25MHz crystal/oscillator or
50MHz oscillator REF_CLK as clock source

Built-in 49.9ohm resistors for simplifying
BOM
Flexible LED display
Process: 85nm

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Source: https://maker.wiznet.io/forum/11704