PCF8574ADWR

I/o Expanders Overview

The PCF8574ADWR is an 8-bit I/O expander for the I2C bus, manufactured by Texas Instruments. It operates within a supply voltage range of 2.5V to 6V and supports a maximum clock frequency of 100 kHz. The device features an 8-bit quasi-bidirectional I/O port (P0–P7) with latched outputs capable of driving LEDs directly. It includes an open-drain interrupt output and requires no data-direction control signal. The component is housed in a 16-pin SOIC package with dimensions of 10.30mm x 7.50mm. Operating temperatures range from -40°C to 85°C.

I/o Expanders Feature Summary

• Provides remote I/O expansion via the two-line bidirectional I2C interface
• Features latched outputs with high-current drive capability for direct LED driving
• Generates interrupts on any rising or falling edge of port inputs without microcontroller polling

I/o Expanders Applications

• Telecom shelters: filter units
• Servers
• Routers (telecom switching equipment)
• Personal computers
• Industrial automation

I/o Expanders Procurement Notes

Verify the specific ordering suffix 'DWR' corresponds to the SOIC-16 package and tape-and-reel packaging configuration. Confirm that the device meets RoHS compliance standards required for the target assembly process. Ensure the supplier provides valid traceability documentation for production-grade components.

I/o Expanders Selection Notes

Select this component when GPIO expansion is needed for microcontrollers lacking sufficient pins. The PCF8574A variant uses a different address offset than the standard PCF8574; verify address compatibility with existing I2C bus designs. Consider the open-drain interrupt feature if event-driven input monitoring is required instead of continuous polling.

I/o Expanders Part Context

This part belongs to the PCF8574A family of remote 8-bit I/O expanders designed for I2C communication. It serves as a peripheral device to extend processor capabilities in systems with limited general-purpose input/output lines. The 'A' designation indicates a specific I2C slave address configuration distinct from the non-A version.

I/o Expanders Replacement Considerations

PCF8574DWRE4

I/o Expanders FAQ

How are the I/O ports configured?

Each quasi-bidirectional I/O can be used as an input or output without a data-direction control signal. At power-on, all I/Os are high.

What is the function of the INT pin?

The INT pin is an open-drain output that signals the microcontroller when an input state change occurs on any port, eliminating the need for constant polling.

Can this device drive LEDs directly?

Yes, the device features latched outputs with high-current drive capability specifically designed for directly driving LEDs.