Product Overview: NXP PCF8574 I/O Expander

The NXP PCF8574 is an 8-bit I/O expander that provides a simple solution for adding additional I/O ports to a microcontroller or processor with I2C interface. It is particularly useful in applications where pins on a microcontroller are limited and more inputs or outputs are required. The device's ability to interface with the I2C bus allows for seamless communication and control via just two wires, making it an efficient choice for expanding the I/O capabilities of your system.

Key Features

• I2C Interface: The PCF8574 communicates over a bidirectional I2C-bus and supports multiple devices on the same bus, allowing for a flexible and expandable I/O configuration.
• 8-bit Remote I/O Ports: Each PCF8574 provides an additional eight I/O ports that can be configured as inputs or outputs.
• Interrupt Output: An interrupt output is available and is activated when any input state differs from its corresponding input port register state. This is especially useful for monitoring input changes without the need for constant polling by the host microcontroller.
• Low Standby Current: The device is designed for low power consumption, with a typical standby current of only 10μA, making it suitable for battery-powered applications.
• Address Pins: Three hardware address pins allow up to eight PCF8574 devices on the same I2C bus, providing up to 64 additional I/O ports.

Applications

The versatility of the PCF8574 makes it ideal for a wide range of applications, including:

• Expanding I/O ports in microcontroller-based systems
• Server infrastructure and industrial control systems
• Home automation and smart appliances
• Robotics and embedded system projects

Product Specifications

With an operating voltage range of 2.5V to 6V, the PCF8574 is compatible with most microcontroller logic levels. It supports I2C bus speeds of up to 400 kHz and is available in various packages, including DIP, SO, and SSOP, to suit different design requirements.