Name: PCF8575 IO Expander Module I2C to 16 – Easyelecmodule
Price: 3.46 USD
Availability: InStock

PCF8575 IO Expander Module I2C to 16

$3.461pcs

PCF8575 Module, I2C controls 16 IO ports, compact & easy integration, universal for mainstream MCUs, plug-and-play

Dimensions

32.5 × 21.3 mm

Brand

easyelecmodule

4213 in stock

Product Introduction

The PCF8575 is a classic chip that expands 16 quasi-bidirectional I/O ports via the I2C bus. Its function is to provide additional GPIO for the main controller through a simple two-wire interface, with each pin configurable independently as input or output. Its working principle is to convert between I2C serial data and parallel I/O; the internal weak pull-up structure gives it the “quasi-bidirectional” characteristic — writing 1 allows the pin to be pulled low externally for input, while writing 0 enables strong pull-down for output.

Its core advantages include greatly saving main controller pin resources, supporting multi-chip cascading for expansion, providing interrupt notification, and featuring strong sink current capability to directly drive loads like LEDs. Typical applications include sensor matrix reading in industrial control, multi-channel key scanning in consumer electronics, and LED array driving, which all demand low-cost and high-density digital I/O expansion scenarios.

Product Description

This powerful module allows users to expand up to 16 I/O ports with only two I/Os for control. The PCF8575 is controlled via an I2C interface and features 16-bit quasi-bidirectional input/output pins. On the onboard 3.3V level shifter circuit, if soldered, its level will be the same as VCC.

Key Parameters

Available Library: PCF8575
Operating Voltage Range: DC 2.5V to 5.5V
Operating Current: 100mA (MAX)
I2C Address: 0x20 (Default). It can be modified by soldering the A1 and A2 pads.
16 individually addressable pins
Each pin can be configured as an input or an output.
Open-Drain Interrupt Output Pin, used for input change interrupts.
It can be applied to UNO R3 and other MCUs for controlling simple relays, buzzers, buttons, and LEDs.

Product Feature

1.Minimal Wiring: Adopts an I2C bus design, requiring only 2 wires (SCL for clock line and SDA for data line) to save the main controller’s IO resources.

2.Flexible Configuration: The 16 channels of IO can independently serve as inputs or outputs without a direction register, and automatically switch via level status (high level for input, low level for output).

3.Wide Voltage Compatibility: Supports 2.5V-5.5V power supply, with an on-board level conversion circuit, directly compatible with 3.3V systems (e.g. ESP32) or 5V systems (e.g. Arduino Uno).

4.Stable and Reliable: Each IO channel has a built-in 100KΩ pull-up resistor for strong anti-interference capability; supports interrupt output (INT pin), which can trigger the main controller interrupt when the input status changes.

Pin Description

Pin Description	PCF8575
P00-P07	P-type port input/output
P10-P17	P-type port input/output
SCL	Serial Clock Line
SDA	Serial Data Cable
VCC	Power Supply Positive
GND	Ground
INT	Interrupted Output
VDD	Positive Pole

Application

Telecom Shelter: Filter Unit
Server
Router
Personal Computer
Personal Electronic Products
Industrial Automation
Products Adopting Processors with Limited GPIO

Relative Information

PCF8575 DataSheet

PCF8575 I2C Expander Hands-On: How to Use 16 IO? Solder After Watching

Shipping Cost

We only ship to the United States. Shipping costs are calculated based on the total order amount.

Shipping Method And Delivery Time

All orders will be processed and shipped within 72 hours of placing the order (excluding weekends and holidays). They will ship from Shenzhen, China, primarily via 4PX logistics. Depending on the destination and logistics conditions, other carriers such as DHL, FedEx, UPS, USPS, etc., may also handle the delivery. Estimated shipping time is 7-12 business days, with actual delivery occurring in 10-17 business days, depending on logistics conditions.