PCA8574PW,118

I/o Expanders Overview

The PCA8574PW,118 is an 8-bit I/O expander for the I2C-bus manufactured by NXP Semiconductors. It provides general-purpose remote I/O expansion via a two-wire bidirectional serial interface operating at frequencies up to 400 kHz. The device features eight quasi-bidirectional ports that default to inputs with weak internal pull-ups upon power-on reset. It operates within a supply voltage range of 2.3 V to 5.5 V and includes three hardware address pins to support up to eight devices on a single bus. An active LOW open-drain interrupt output signals input state changes to the microcontroller. The component is housed in a TSSOP16 plastic thin shrink small outline package (SOT403-1) and supports an ambient operating temperature range from -40 °C to +85 °C.

I/o Expanders Feature Summary

• Eight quasi-bidirectional I/O ports with latched outputs capable of directly driving LEDs
• Active LOW open-drain interrupt output for efficient event notification without polling
• Three hardware address inputs allowing multiple devices on a single I2C bus
• Internal Power-On Reset initializes all I/Os as inputs with weak pull-up current sources

I/o Expanders Applications

• LED signs and displays
• Industrial control systems
• Key pads
• Medical equipment
• PLCs

I/o Expanders Procurement Notes

Verify the ordering suffix '118' corresponds to the Reel 13” Q1/T1 packing method specified in the datasheet. Confirm the manufacturer is NXP Semiconductors and the package type matches the TSSOP16 variant. Ensure the part number aligns with the standard marking requirements for this specific reel configuration.

I/o Expanders Selection Notes

Select this component when an 8-bit I/O expander with interrupt capability is required for I2C communication. It serves as a drop-in replacement for the PCF8574T/3 series. Consider the 400 kHz Fast-mode I2C interface and the 2.3 V to 5.5 V operating voltage range. Verify compatibility with the TSSOP16 package dimensions if space constraints exist.

I/o Expanders Part Context

This part belongs to the PCA8574 family of remote 8-bit I/O expanders. It shares functional similarities with the PCF8574 but offers improved performance characteristics such as higher I2C speed and greater sink current capability. The PCA8574A variant exists with a different fixed slave address portion to allow mixed usage on the same bus.

I/o Expanders Replacement Considerations

The datasheet identifies the PCA8574D as a drop-in replacement for the PCF8574T/3. For migration to newer packages, consider the PCA9674 or PCA9670 series which offer increased addressability and Fm+ speeds.