PCF8574DWRG4

I/o Expanders Overview

The PCF8574DWRG4 is an 8-bit I/O expander for the two-line bidirectional I2C bus, designed for VCC operation between 2.5V and 6V. It provides general-purpose remote I/O expansion via SCL and SDA pins. The device features an 8-bit quasi-bidirectional I/O port (P0–P7) with latched outputs capable of directly driving LEDs. Each I/O functions as input or output without a data-direction control signal. At power-on, I/Os are high. It includes an open-drain interrupt output triggered by rising or falling edges on port inputs.

I/o Expanders Feature Summary

• I2C to parallel-port expander
• Open-drain interrupt output
• Latched outputs with high-current drive capability

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 package type against the datasheet, as the 'DW' suffix indicates SOIC-16. Confirm RoHS compliance status through official Texas Instruments documentation. Ensure the ordering suffix matches the required tape-and-reel or tube packaging format for your assembly process. Cross-reference the full part number with the manufacturer's current product folder to confirm availability and lifecycle status.

I/o Expanders Selection Notes

Select this component when GPIO resources are limited on the host microcontroller. It supports standard-mode I2C clock frequencies up to 100 kHz. The device operates within a wide supply voltage range from 2.5V to 6V. Consider the interrupt pin functionality if real-time input detection is required without continuous polling. Ensure the I2C bus capacitance does not exceed 400 pF for reliable communication.

I/o Expanders Part Context

The PCF8574DWRG4 belongs to the PCF8574 family of remote 8-bit I/O expanders. The 'DW' designation specifies the SOIC-16 package variant. This series is widely used for expanding microcontroller ports in embedded systems. Other variants include PDIP, TSSOP, and VQFN packages. The device is compatible with most microcontroller families utilizing the I2C interface.

I/o Expanders Replacement Considerations

PCF8574DGVR

I/o Expanders FAQ

How is the I2C address configured?

The 7-bit I2C address is determined by the logic levels on the A0, A1, and A2 pins. These pins can be connected directly to VCC or GND to select one of eight possible addresses.

What triggers the INT output?

An interrupt is generated by any rising or falling edge of the port inputs when they are in input mode. The INT pin goes low to signal the microcontroller.

Does the device have internal configuration registers?

No, the PCF8574 does not have internal configuration or status registers. Read or write operations access the I/O ports directly after sending the device address.