IC Port Expander 8Bit Outputs I2C PCF8574P

AED 7.35



The PCF8574 is an 8-bit I/O port expander IC that extends the I/O capabilities of a microcontroller via an I2C bus. It increases the digital I/O count to 21 when used with an Arduino UNO board, with pins configurable as either input or output.



  • I/Os: The PCF8574 provides 8 I/O ports, expanding the digital I/O capabilities of the microcontroller it's connected to. These ports can be individually configured as either inputs or outputs, allowing for versatile interfacing with external devices.
  • Interrupt: Pin: Featuring an interrupt pin (INT), the PCF8574 can generate interrupts to the microcontroller upon detecting specific events or conditions. This feature enhances real-time responsiveness in applications, enabling prompt action based on external stimuli.
  • Supply Voltage (Min): 2.5V: The PCF8574 operates reliably with a minimum supply voltage of 2.5V. This low operating voltage requirement makes it suitable for use in low-power applications or with power sources that provide limited voltage output.
  • Supply Voltage (Max): 6V: With a maximum supply voltage tolerance of 6V, the PCF8574 accommodates a wide range of power sources commonly used in electronic circuits. This ensures compatibility with various system configurations and voltage levels.
  • Addresses: 8: It supports 8 unique I2C addresses, enabling multiple PCF8574 devices to coexist on the same I2C bus without address conflicts. This feature facilitates the expansion of I/O capabilities by allowing several PCF8574 modules to be interconnected in a system.
  • Frequency (Max): 100 kHz: The PCF8574 supports a maximum I2C communication frequency of 100 kHz. This high-frequency capability ensures efficient data transfer between the microcontroller and the PCF8574, enabling fast and reliable communication in diverse applications.
  • Operating Temperature Range: -40°C to 85°C: Designed to withstand harsh environmental conditions, the PCF8574 operates reliably within a wide temperature range from -40°C to 85°C. This temperature tolerance makes it suitable for use in industrial, automotive, and commercial applications subjected to varying environmental temperatures.



  • Number of I/Os: 8
  • Interrupt: Pin
  • Supply Voltage (Min): 2.5V
  • Supply Voltage (Max): 6V
  • Addresses: 8
  • Frequency (Max): 100 kHz
  • Operating Temperature Range: -40°C to 85°C


PCF8574 Pinout:

Pin Number Pin Name Description
1, 2, 3 A0, A1, A2 Address Inputs
4-7, 9-12 P0 - P7 Input / Output Port
8 GND Ground
13 INT Interrupt Output (Must be pulled high to VCC)
14 SCL Serial Clock of I2C (Must be pulled high to VCC)
15 SDA Serial Data of I2C (Must be pulled high to VCC)
16 VCC Voltage Supply


PCF8574 Connections with Arduino:

PCF8574 Pin Arduino Connection
A0-A2 To change the address
P0-P7 I/O
INT Not Connected


Package Includes:

  • 1 x PCF8574 IC