WIZ850io

WIZ850io

The WIZ850io is a compact network module that integrates the W5500 hardwired TCP/IP chip with a built-in PHY, transformer, and RJ45 MAG-JACK.
It is fully compatible with WIZ820io hardware, providing developers with a seamless upgrade path and faster network performance.
Ideal for rapid prototyping and Internet-enabled embedded systems, it requires no additional interface design between the W5500 and transformer.

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Pin Information

All

J1 — SPI Interface

Pin	Type	Name	Description
1	P	GND	Ground
2	P	GND	Ground
3	I	MOSI	SPI Master-Out / Slave-In
4	I	SCLK	SPI clock input
5	I	SCNn	SPI chip select (active low)
6	O	INTn	Interrupt output (low-active) — indicates socket events like connection, disconnection, data reception, and WOL

J2 — Power & Control

Pin	Type	Name	Description
1	P	GND	Ground
2	P	3V3D	3.3 V Power supply
3	P	3V3D	3.3 V Power supply
4	–	NC	Not connected
5	I	RSTn	Hardware reset input (active low, ≥ 500 µs)
6	O	MISO	SPI Master-In / Slave-Out

Wait at least 50 ms after RSTn goes high before SPI communication.

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Features

• Compact plug-in Ethernet module integrating W5500 with transformer and RJ45 MAG-JACK
• Hardware compatible with WIZ820io
• No hardware design required for PHY or transformer
• Supports high-speed SPI interface (Mode 0/3)
• Power-down and Wake-on-LAN support
• Small form factor: 20 × 25 mm
• 1×6-pin headers (2.54 mm pitch)
• Operating temperature: −40 °C ~ +85 °C

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Electrical Characteristics

DC Characteristics

Symbol	Parameter	Pins	Min	Typ	Max	Unit
VDD	Supply voltage	3.3 V	2.97	3.3	3.63	V
VIH	High-level input	ALL	0.7×Vcc	–	5.5	V
VIL	Low-level input	ALL	–0.3	–	0.3×Vcc	V
VOH	High-level output	ALL	2.9	3.3	–	V
VOL	Low-level output	ALL	0.0	–	0.52	V
IDD	Supply current (Normal)	3.3 V	–	141	–	mA
IPD	Supply current (Power-down)	3.3 V	–	13	–	mA

Power Dissipation

Condition	Min	Typ	Max	Unit
100 Mb/s Link	–	135	–	mA
10 Mb/s Link	–	80	–	mA
Unlink (Auto-negotiation)	62	–	75	mA
100 Mb/s Tx	137	–	141	mA
10 Mb/s Tx	–	83	–	mA
Power-down	–	13	–	mA

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Documentation

This section provides key documentation, including user manuals and datasheets, to help you understand product features, specifications, and usage.

Title	Description	Link	Notes
Datasheet	Technical specifications and features of the W5500 chip	EN / 한국어	-

note

SPI operation of W5500-io follows one of W5500. For more information about SPI operation of W5500-io, please refer to W5500 Datasheet.

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Software Resources

Driver

Driver

Resource	Description
ioLibrary_Driver	Official WIZnet driver library for W5500 and other chips

info

The ioLibrary_Driver is an MCU-independent library for WIZnet W5x00, W6x00 chips . It provides implementations of essential TCP/IP services, enabling developers to build network applications with minimal MCU dependencies. Supported services
DHCP, DNS, MQTT, SNTP, TFTP, HTTP Server

Application Note

Application Note

Example Name	Description	Notes
TCP Function	How to use TCP Function	ITCP Function handles IPv4 layer communication
UDP Function	How to use UDP Function	UDP Function handles IPv4 layer communication
IPRAW	How to use IPRAW Mode	IPRAW Mode handles IPv4 layer communication
PPPoE	How to use PPP/PPPoE	PPP is Link-Layer protocol for point-to-point

info

These application notes explain how to use W5500's core networking functions including TCP, UDP, IPRAW mode, and PPPoE protocols.

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Hardware Resources

Title	Revision	Description	Download	Notes
Schematic	1.0	Circuit diagram for reference	PDF Altium ZIP
Schematic	1.1	Updated circuit and layout	PDF Altium ZIP

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Mechanical Information

• Form factor: Plug-in ioModule
• Pin pitch: 2.54 mm
• Dimensions: 25 × 23 mm

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Related Products

Product	Description
W5500 Chip	Hardwired TCP/IP Ethernet controller with integrated PHY