---
title: "Question about shematic"
url: "https://maker.wiznet.io/forum/11228"
markdown_url: "https://maker.wiznet.io/forum/11228/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "kavireloot"
created: "2015-08-15T15:20:22+09:00"
last_activity: "2017-05-04T08:36:36+09:00"
language: "en"
views: 363
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Question about shematic

## Question

Asked by kavireloot on 2015-08-15 in Ethernet Chips.

should i use buffer between pins SCS and SEN?

## Replies

### Reply 1 by kavireloot, 2015-08-16

Im waiting for your answer , please give me a hand…

### Reply 2 by Coccoliso, 2015-08-16

Hi.
I suggest using only 3.3V signals, if you use 5v put a buffer ON ANY SIGNAL also on 5v compatible pin to remove any delay.
If you have to use SPI put SEN high or low if use parallel mode… do not need the buffer.

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Source: https://maker.wiznet.io/forum/11228