PCA9555DW

I/o Expanders Overview

The PCA9555DW is a 24-pin CMOS device providing 16 bits of general-purpose parallel input/output expansion for I2C and SMBus applications. It operates within a supply voltage range of 2.3 V to 5.5 V and supports a maximum clock frequency of 400 kHz. The component features an interrupt output pin that activates when any input state differs from its corresponding input port register state. It includes configuration, input, output, and polarity inversion registers, allowing individual I/O selection as inputs or outputs. The device offers 5 V I/O tolerance and internal pull-up resistors on each channel.

I/o Expanders Feature Summary

• Provides 16-bit GPIO expansion compatible with I2C and SMBus protocols
• Features an open-drain interrupt output activated by input state changes
• Includes configurable registers for input/output selection and polarity inversion

I/o Expanders Applications

• ACPI power switch control
• Sensor interface expansion
• Pushbutton and LED monitoring systems

I/o Expanders Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to ensure package and temperature grade alignment. Confirm RoHS compliance status through official datasheets or certified distributor declarations prior to procurement. Cross-reference the part number with the latest product change notifications to identify any manufacturing updates or lifecycle status changes.

I/o Expanders Selection Notes

Select this component when additional digital I/O lines are required for microcontrollers with limited pins. Ensure the system voltage matches the 2.3 V to 5.5 V operating range. Verify that the I2C address configuration meets system requirements. Consider the SOIC-24 package constraints for PCB layout and thermal management in the final design.

I/o Expanders Part Context

The PCA9555 series enhances the Philips family of I2C I/O expanders with higher drive capability and lower supply current. It is pin-to-pin and I2C address compatible with the PCF8575 but requires software adjustments due to architectural enhancements. The device simplifies system design by reducing pin count and board space while maintaining robust communication capabilities.

I/o Expanders Replacement Considerations

The PCF8575 is electrically compatible but may require software modifications due to functional differences. Verify register mapping and interrupt behavior before substitution. Other 16-bit I2C expanders from different manufacturers may lack specific features like internal pull-ups or identical interrupt logic.