---
title: "iEthernet W5500"
url: "https://maker.wiznet.io/forum/13006"
markdown_url: "https://maker.wiznet.io/forum/13006/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "seanmesh"
created: "2018-07-20T15:51:27+09:00"
last_activity: "2018-07-20T20:29:45+09:00"
language: "en"
views: 741
replies: 4
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# iEthernet W5500

## Question

Asked by seanmesh on 2018-07-20 in Ethernet Chips.

Greetings,

Please advise where can the input capacitance for the W5500 XI/CLKIN pin (#30) be found or how can it be calculated.

Thanks,

Shalmon

## Replies

### Reply 1 by Eugeny, 2018-07-20

[Crystal Selection Guide Application Note](https://wizwiki.net/wiki/lib/exe/fetch.php?media=products:w5100s:w5100s_crystal_selection_guide_v100e.pdf).

### Reply 2 by seanmesh, 2018-07-20 (in reply to reply 1)

Thanks Eugene, though I’ll need the actual input capacitance as I’m driving multiple ICs with a single oscillator.

### Reply 3 by Eugeny, 2018-07-20

Oscillator or generator? Crystal oscillator will require both XI and XO, and I doubt you can connect an oscillator to two chips (it will require buffering at least). If you talk about generator (buffered oscillator), then you can take approx 10 pF for W5500 internal capacitance.

### Reply 4 by seanmesh, 2018-07-20

Yes, oscillator (CB3LV-3C-25M0000) not crystal.

10pF sounds high, i didn’t work with ICs that have more than 5pF capacitance on their clock input pin. Is there an actual electrical characteristics table? Someone/somewhere must posses this kind of information…

thanks anyways

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Source: https://maker.wiznet.io/forum/13006