# IO port expansion module, PCF8575, I2C, 16 ports, 2.5-5.5V

> IO expansion module with PCF8575 chip, I2C communication, featuring 16 individually configurable input/output ports. Operates at 2.5-5.5V DC, maximum current 100mA, default I2C address 0x20 (changeable via A1/A2 solder pads). Includes onboard 3.3V logic level converter and open-drain interrupt pin. Dimensions: 32 x 22mm. Suitable for relays, LEDs, buttons, buzzers.

- Page: https://sigmanortec.ro/en/io-port-expansion-module-pcf8575-i2c-16-ports-25-55v
- Price: 14.47 RON
- Availability: In stock; 1-2 zile
- Reference: 9717 · EAN: 5943828306723
- Category: Mechatronics and IoT > Sensors and Modules > Expansion Module
- Specifications: Input Voltage: 2.5 - 5.5 V; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.006 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 01:33 (Europe/Bucharest)

## Description

Quickly expand your microcontroller's I/O with 16 I2C-controlled ports using only SDA and SCL. It operates at 2.5-5.5V and is compatible with 3.3V or 5V boards thanks to the integrated level converter. Each pin is independently set as input or output, and the open-drain interrupt pin signals changes, ideal for relays, LEDs, buttons and buzzers.
PCF8575 expansion module, compatible with Arduino and other development boards on both 3.3 and 5V.
This is an I2C device that allows users to expand the I/O capabilities of the microcontroller with up to 16 I/O ports, using only I2C pins.
It works at a voltage of 2.5-5.5V DC and has a maximum operating current of 100mA.
The I2C address is 0x20 (default), which can be changed by pasting the selection areas A1 and A2. Each pin can be individually configured as an input or output, and includes an open-drain output pin for interrupts when the input changes. It is ideal for UNO R3 and other MCUs for controlling simple relays, buzzers, buttons, LEDs.
On the board there is a 3.3V logic level converter circuit. If on the board VCC and VDD are not short-circuited (on the back), the reference and logic voltage is 3.3V. If they are connected, the logic voltage is equal to the voltage present on the VCC pin.
Specifications:
Working Voltage: 2.5-5.5V DC
Communication Interface: I2C
I2C address: 0x20 (default), modifiable by gluing pads A1 and A2
Operating Current: Maximum 100mA
Number of I/O Ports: 16 individual ports
Port Configuration: Each pin configurable as input or output
Interrupt Output: Open-drain for interrupts when the input changes
Shift Level: 3.3V onboard circuit. The PCF8575 level is 3.3V, or equal to VCC if the VCC-VDD pad is soldered
Dimensions mm: 32 x 22mm