---
title: "Are the W5500 products we have original or fake ?"
url: "https://maker.wiznet.io/forum/16095"
markdown_url: "https://maker.wiznet.io/forum/16095/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Huseyin_Ozdil"
created: "2026-06-12T14:59:03+09:00"
last_activity: "2026-06-15T09:45:31+09:00"
language: "en"
tags: ["W5500"]
views: 8
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Are the W5500 products we have original or fake ?

## Question

Asked by Huseyin_Ozdil on 2026-06-12 in Ethernet Chips.

Could one of the W5500 chips shown in the attached image be fake?

The unstable devices were purchased from local distributors between 2020 and 2023, and all of them have the same markings and appearance. The stable devices use W5500 chips purchased directly from DigiKey, as shown on the right side of the attached image.

Attachments:

- [W5500.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=383)

## Replies

### Reply 1 by lawrence, 2026-06-15

Hi Huseyin_Ozdil,

Thank you for the detailed description and for sharing the comparison photos. Placing the two parts side by side really helps us understand the situation accurately.

To be upfront: we cannot confirm authenticity from photographs alone. Looking at your images, the top-side markings on both chips (the WIZnet logo, the W5500 part number, the trace code, and the YYWW date code) fall within the normal range.

We also noticed that the backside surface texture and corner markings differ between the two parts. However, this difference alone is not enough to conclude that a part is counterfeit. Lots produced at different times can legitimately differ in backside appearance, because the assembly subcontractor, mold compound, and laser-marking equipment can change between production runs — so genuine parts from different periods may also show backside variation.

For that reason, the more important signal here is the "instability" you described in operation, rather than the external appearance. To investigate this properly, it would help if you could provide the following so we can verify through our official process:

1. The full trace/lot code printed on the unstable parts (in addition to DQK580 in the photo, if there are other codes, please include them).
2. The name of the supplier (local distributor) and the purchase date — an invoice or purchase record would be helpful if available.
3. Whether you can send samples for analysis — sending an unstable part would give us the most accurate result.
4. Detailed description of the unstable behavior you found from unstable IC - Link issue, SPI access issue, TCP/UDP communication issue, reset issue, etc.

By cross-checking the trace code against our production and shipment records, we can do a first-level verification of where the part originated. If we receive samples, we can go further with electrical/parametric measurement and package/die comparison to determine both authenticity and the root cause of the instability.

As context, the 2020–2023 period coincided with the global semiconductor shortage, when quality variation in parts sourced through non-authorized channels was unusually common. Going forward, where possible, we would recommend purchasing through authorized channels such as DigiKey, Mouser, or WIZnet's official regional distributors.

Please reply to lawrence@wiznet.io once you have the information and samples ready, and we will help you promptly. Thank you.

Best regards,
Lawrence

---

Source: https://maker.wiznet.io/forum/16095