Texas Instruments

PCF8574APW

PCF8574APW Description

The PCF8574APW is an I/O expander designed by Texas Instruments, featuring 8-bit quasi-bidirectional I/O lines with interrupt output. It operates within a supply voltage range of 2.5V to 6V and supports a clock frequency of 100 kHz. This surface-mount device is compliant with the RoHS3 directive and is categorized under EAR99 for export control classification. The product is currently marked as obsolete, indicating that it may not be readily available for new designs. Despite this, it remains a viable option for legacy systems or specific applications where its features are required.

PCF8574APW Features

• Interface: I2C, simplifying communication with microcontrollers and other digital systems.
• Number of I/O: 8 quasi-bidirectional I/O lines, providing flexibility for various digital input/output requirements.
• Current - Output Source/Sink: Capable of sourcing 1mA and sinking 25mA, suitable for driving a range of digital loads.
• Voltage - Supply: Operates over a wide voltage range of 2.5V to 6V, making it compatible with various power sources.
• Interrupt Output: Includes an interrupt output line, which can be used to signal the host microcontroller when an interrupt condition occurs.
• Features: Incorporates a Power-On Reset (POR) feature, ensuring reliable startup and operation.
• Package: 20-lead TSSOP package, suitable for space-constrained applications.
• Moisture Sensitivity Level (MSL): Rated at level 1, indicating unlimited storage time before baking is required.

PCF8574APW Applications

The PCF8574APW is ideal for applications where digital I/O expansion is needed with minimal wiring complexity. Some specific use cases include:

• Industrial Control Systems: For expanding digital I/O in automation and control systems.
• Home Automation: To control and monitor various smart home devices through a central microcontroller.
• Portable Electronics: In devices where space is at a premium, the small footprint of the TSSOP package is advantageous.
• Retro-Fitting and Legacy Systems: For systems that require the addition of digital I/O without extensive modifications to the existing hardware.

Conclusion of PCF8574APW

While the PCF8574APW is an obsolete product, it still offers a robust solution for applications requiring I/O expansion with I2C interface. Its wide voltage range, interrupt capability, and quasi-bidirectional I/O lines make it suitable for a variety of digital control and monitoring tasks. Although it may not be the first choice for new designs due to its obsolescence, it remains a reliable option for specific applications and legacy systems where its unique features are beneficial.