PCA9555PW,112

I/o Expanders Overview

The PCA9555PW,112 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 a 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 packaging. It includes an active LOW interrupt output, polarity inversion registers, and internal power-on reset functionality. The ordering suffix ,112 indicates standard marking ICs in a tube bulk pack format.

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 an open-drain interrupt output activated by input state changes
• Supports up to eight devices on a single bus via three hardware address pins

I/o Expanders Applications

• ACPI power switches
• Sensor interface connections
• Push button arrays
• LED control circuits
• Fan monitoring systems

I/o Expanders Procurement Notes

Verify the specific ordering suffix ,112 against official NXP documentation to confirm the package type and packing method. Ensure the procurement channel sources directly from authorized distributors to guarantee component authenticity. Cross-reference the part number with the latest datasheet revision to confirm compatibility with current manufacturing standards.

I/o Expanders Selection Notes

Select this component when additional I/O capacity is required for microcontrollers with limited pins. The 5 V tolerant I/Os allow direct interfacing with various logic levels without external level shifters. Consider the TSSOP24 package dimensions for PCB layout constraints and verify that the I²C bus speed requirements do not exceed 400 kHz.

I/o Expanders Part Context

The PCA9555 series enhances the NXP Semiconductors family of I²C-bus I/O expanders by offering higher drive capability and lower supply current compared to predecessors like the PCF8575. While pin-to-pin and address compatible with older models, software adjustments are necessary due to enhanced register configurations. This specific part belongs to the broader PCA9555 product line designed for efficient serial-to-parallel conversion.

I/o Expanders Replacement Considerations

The PCF8575 is pin-to-pin and address compatible but requires software changes due to functional enhancements in the PCA9555. Other members of the PCA9555 family, such as PCA9555D or PCA9555DB, offer identical electrical characteristics but differ in physical packaging formats.