PCA9555PW,118

I/o Expanders Overview

The PCA9555PW,118 is a 24-pin CMOS device providing 16-bit General Purpose parallel Input/Output (GPIO) expansion for I2C-bus and SMBus applications. It operates within an operating power supply voltage range of 2.3 V to 5.5 V and supports clock frequencies from 0 Hz to 400 kHz. The device features five packages, with the PW variant utilizing TSSOP24 plastic thin shrink small outline package (SOT355-1). It includes polarity inversion registers, active LOW interrupt output, noise filters on SCL/SDA inputs, and internal power-on reset. ESD protection exceeds 2000 V HBM per JESD22-A114.

I/o Expanders Feature Summary

• Provides 16 bits of GPIO expansion compatible with I2C-bus and SMBus protocols
• Features individual I/O configuration allowing independent input or output selection
• Includes open-drain interrupt output activated by input state changes

I/o Expanders Applications

• ACPI power switches
• Sensors
• Push buttons
• LEDs
• Fans

I/o Expanders Procurement Notes

Verify the ordering suffix '118' corresponds to the specific reel packing method required for your assembly line. Confirm that the TSSOP24 package dimensions align with your PCB footprint design rules before finalizing procurement orders.

I/o Expanders Selection Notes

Select this component when additional I/O capacity is needed for systems using I2C or SMBus interfaces. Ensure the system voltage falls within the 2.3 V to 5.5 V range and verify that the 400 kHz maximum clock frequency meets communication speed requirements.

I/o Expanders Part Context

Developed to enhance the NXP Semiconductors family of I2C-bus I/O expanders, the PCA9555 offers higher drive capability, 5 V I/O tolerance, lower supply current, and smaller packaging compared to predecessors. It maintains pin-to-pin and address compatibility with the PCF8575, though software adjustments are necessary due to its enhanced features.

I/o Expanders Replacement Considerations

The PCF8575 is pin-to-pin and I2C-bus address compatible but requires software changes due to functional enhancements in the PCA9555.