PCF8574ADWE4

I/o Expanders Overview

The PCF8574ADWE4 is a remote 8-bit I/O expander for the I2C bus manufactured by Texas Instruments. It operates within a supply voltage range of 2.5 V to 6 V and supports an I2C clock frequency up to 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 (INT) for event-driven communication. The component is housed in a 16-pin SOIC package and functions across an operating temperature range of -40°C to +85°C.

I/o Expanders Feature Summary

• Provides general-purpose remote I/O expansion via the two-line bidirectional I2C interface.
• Features an 8-bit quasi-bidirectional I/O port with latched outputs for high-current drive capability.
• Includes an open-drain interrupt output to signal microcontrollers without continuous bus polling.

I/o Expanders Applications

• Telecom shelters, including filter units
• Servers and routers for telecom switching equipment
• Personal computers and personal electronics
• Industrial automation systems
• Products utilizing GPIO-limited processors

I/o Expanders Procurement Notes

Verify the specific ordering suffix 'DWE4' against the manufacturer's current orderable addendum to confirm package type and availability. Ensure the procurement source provides valid traceability documentation. Confirm that the component meets RoHS compliance requirements as specified in the official datasheet before finalizing purchase orders.

I/o Expanders Selection Notes

Select this component when expanding I/O capabilities for microcontrollers using the I2C protocol. It is suitable for applications requiring direct LED driving due to its latched output structure. Consider the 16-pin SOIC package constraints and ensure the system voltage falls within the 2.5 V to 6 V operational range. Verify that the I2C bus capacitance does not exceed 400 pF for standard-mode operation.

I/o Expanders Part Context

This part belongs to the PCF8574A family of remote 8-bit I/O expanders. The 'DW' suffix indicates the 16-pin SOIC package variant. The 'E4' suffix typically denotes environmental compliance or lead-free status according to Texas Instruments naming conventions. It serves as a peripheral device to extend the input/output capacity of main controllers over the I2C bus.

I/o Expanders Replacement Considerations

PCF8574APWRE4: Pin-compatible alternative in TSSOP-20 package.

I/o Expanders FAQ

How is the interrupt function reset on the PCF8574A?

The interrupt circuit resets when data on the port generating the interrupt is changed to its original setting, or when data is read from or written to that specific port.

What is the default state of the I/O pins at power-on?

At power-on, all I/Os are high. In this mode, only a current source to VCC is active, allowing them to be used as inputs immediately.

Can the PCF8574A respond to general call addresses?

No, the device does not respond to the general call address on the I2C bus; it only responds to its specific configured address.