---
title: "w5500 not working (circuit)"
url: "https://maker.wiznet.io/forum/9465"
markdown_url: "https://maker.wiznet.io/forum/9465/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "tony_90"
created: "2024-09-13T19:39:05+09:00"
last_activity: "2024-09-19T14:22:09+09:00"
language: "en"
views: 6
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# w5500 not working (circuit)

## Question

Asked by tony_90 on 2024-09-13 in Ethernet Chips.

w5500 not working (circuit)

Hello, we are using w5500 ic and have some questions.
Currently, the lights on the Internet connection route are not on.
1. The oscillator vibrates (average 1.7 volts on one side, 1.6 volts on the other side, 25mHz)
2. The voltage of the 12.4k resistor is 0.7 volts
The schematic diagram is as follows. Please give me some advice. Thank you.
with best regards

Attachments:

- [w5500_.PNG](https://maker.wiznet.io/forum/getAttach.asp?aidx=104)

## Replies

### Reply 1 by tony_90, 2024-09-18

At present, I think the problem is caused by the strict requirements of w5500 for crystal . I want to change to an active oscillator, but the official only says that the requirements of W5500 are: the active crystal oscillator inputs the clock signal through the XI/CLKIN pin, and the signal level requirement is 3.3V. Are there any requirements for the waveform? (square wave or sine wave) In addition, 3.3v is not detailed enough (active oscillator output has loss, usually 90% vdd) Is 3.3V the lowest judgment voltage value of high level?
Thank you

### Reply 2 by Alan, 2024-09-19

Hello, I'm Alan.

Please remove 49.9 ohms connected to SPI.

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Source: https://maker.wiznet.io/forum/9465