PCA9554N,112

I/o Expanders Overview

The PCA9554N,112 is an 8-bit I/O expander designed for I2C-bus and SMBus applications. It provides General Purpose parallel Input/Output expansion in a 16-lead SOIC package (SOT162-1). The device operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. It features an active LOW interrupt output that activates when input states change. The component includes hardware address selection via pins A0, A1, and A2, allowing multiple devices on the same bus. All I/O pins default to inputs with weak pull-ups upon power-on reset.

I/o Expanders Feature Summary

• Provides 8 bits of general-purpose parallel input/output expansion controlled via I2C-bus or SMBus interfaces.
• Features an open-drain interrupt output that signals the system master when any configured input state changes.
• Includes a polarity inversion register to allow active HIGH or active LOW operation for input data.
• Supports hardware-selectable slave addresses using three address pins to enable multiple devices on a single bus.

I/o Expanders Applications

• ACPI power switches
• Sensor interface expansion
• Push button matrix scanning
• LED control arrays

I/o Expanders Procurement Notes

Verify the specific ordering suffix '112' corresponds to the tube packing method and standard marking as defined in the official NXP documentation. Confirm the package type matches the required PCB footprint for the SO16 variant. Ensure the fixed I2C address configuration aligns with the system design requirements before procurement.

I/o Expanders Selection Notes

Select this component when additional GPIOs are needed for I2C-connected subsystems. Ensure the system controller supports the required I2C clock speeds up to 400 kHz. Verify that the 5 V tolerant I/Os match the voltage levels of the connected peripherals. Consider the interrupt capability if event-driven input monitoring is required by the application logic.

I/o Expanders Part Context

This part belongs to the PCA9554 family of CMOS devices developed to enhance NXP's I2C-bus I/O expander series. It offers improvements such as higher drive capability, lower supply current, and individual I/O configuration compared to earlier generations. The device is pin-to-pin compatible with the PCF8574 series but requires software adjustments due to its enhanced register architecture.

I/o Expanders Replacement Considerations

The PCA9554A variants share identical functionality but utilize a different fixed I2C address base, permitting up to sixteen devices on one bus when mixed. Direct pin-compatible alternatives include other SO16 I/O expanders, though software modifications may be necessary due to differing register maps and feature sets.