PCF8574DWRE4

I/o Expanders Overview

The PCF8574DWRE4 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 any rising or falling edge 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 suffix 'E4' against the manufacturer's official documentation to confirm it denotes lead-free status or RoHS compliance. Ensure the SOIC-16 package matches the required PCB footprint. Confirm that the operating temperature range of -40°C to 85°C meets the environmental requirements of the target application before finalizing procurement.

I/o Expanders Selection Notes

Select this component when GPIO resources are limited on the main microcontroller. It is suitable for applications requiring low standby current and direct LED driving. Ensure the I2C bus capacitance does not exceed 400 pF. Verify that the open-drain interrupt output aligns with the host controller's interrupt input requirements.

I/o Expanders Part Context

The PCF8574 series is a family of remote 8-bit I/O expanders for I2C buses. The DWRE4 variant specifically refers to the SOIC (Dw) package in tape-and-reel format. This part expands upon earlier versions by offering standardized packaging options for automated assembly while maintaining the core functionality of the original Philips/NXP design now produced by Texas Instruments.

I/o Expanders Replacement Considerations

PCF8574A: Similar functionality but different address bits. TCA9534: Standard push-pull outputs instead of quasi-bidirectional. MCP23008: Push-pull outputs with internal configuration registers.