PCF8574ADW

I/o Expanders Overview

The PCF8574ADW is an 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 a maximum clock frequency of 100 kHz. The device features an open-drain interrupt output and latched outputs with high-current drive capability. It utilizes a TSSOP-20 package and functions across an operating temperature 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 quasi-bidirectional I/O ports that require no data-direction control signal
• Includes an open-drain interrupt output triggered by input state changes

I/o Expanders Applications

• Telecom shelters: filter units
• Servers
• Routers (telecom switching equipment)
• Personal computers
• Products with GPIO-limited processors

I/o Expanders Procurement Notes

Verify the specific suffix 'DW' corresponds to the SOIC-16 package, as datasheets often list 'DW' for SOIC and 'PW' for TSSOP. Confirm RoHS compliance status through official documentation. Ensure the component meets the required thermal resistance specifications for the target PCB layout and ambient operating conditions.

I/o Expanders Selection Notes

Select this component when expanding microcontroller I/O capabilities using the I2C protocol. It is suitable for applications requiring direct LED driving due to its latch-up performance exceeding 100 mA per JESD 78, Class II. Consider the address configuration options provided by the A0-A2 pins for multi-device bus integration.

I/o Expanders Part Context

This part belongs to the PCF8574A family of remote 8-bit I/O expanders. It shares functional characteristics with other variants in the series but differs in physical packaging. The 'A' designation typically indicates a specific I2C slave address offset compared to the standard PCF8574.

I/o Expanders Replacement Considerations

PCF8574APW

I/o Expanders FAQ

How is the interrupt function reset?

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

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

At power-on, the I/Os are high, activating only a current source to VCC.

Can the I/Os be used without a data-direction control signal?

Yes, each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal.