PCA9557PW,112

I/o Expanders Overview

The PCA9557PW,112 is an 8-bit I/O expander manufactured by NXP Semiconductors in a TSSOP16 package. It operates on an I2C-bus/SMBus interface with a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. The device features low standby current (typical 1 µA), internal power-on reset, and an active LOW reset input. It includes noise filters on SCL/SDA inputs and provides ESD protection exceeding 2000 V HBM. Operating temperature ranges from -40 °C to +85 °C.

I/o Expanders Feature Summary

• Provides 8 general-purpose input/output expansion via I2C-bus or SMBus interface
• Includes active LOW reset input for system initialization without power cycling
• Features configurable polarity inversion register for input signal adjustment
• Offers high-impedance open-drain output on IO0 pin

I/o Expanders Applications

• Parallel input/output expansion for SMBus and I2C applications
• Remote control systems requiring isolated I/O boundaries
• Battery-powered devices utilizing low standby current modes

I/o Expanders Procurement Notes

Verify the ordering suffix '112' corresponds to the tube packing method specified in the datasheet. Confirm the package type matches the required PCB footprint. Ensure the operating voltage and temperature ranges align with the target application environment before finalizing procurement.

I/o Expanders Selection Notes

Select this component when an 8-bit I/O expander with I2C compatibility is required. Consider the TSSOP16 package constraints and the need for external pull-up resistors on address pins. Evaluate if the absence of interrupt outputs meets the system timing requirements compared to other variants in the family.

I/o Expanders Part Context

The PCA9557 series serves as a migration path from the PCA9556, offering lower voltage operation and higher performance. It is part of NXP's portfolio of I/O expanders designed for resource-constrained embedded systems. The PW variant specifically denotes the thin shrink small outline package suitable for surface mount assembly.

I/o Expanders Replacement Considerations

PCA9557PW,118 offers identical functionality but utilizes reel packing instead of tubes.