PCA9555PWJ

I/o Expanders Overview

The PCA9555PWJ is a 24-pin CMOS device providing 16-bit General Purpose Input/Output (GPIO) expansion for I²C-bus/SMBus applications. It operates within a supply voltage range of 2.3 V to 5.5 V and features ultra-low standby current consumption with a maximum of 1 µA. The device includes an open-drain active LOW interrupt output, polarity inversion registers, and weak pull-up resistors on all GPIOs. It supports Fast-mode I²C communication up to 400 kHz and allows up to eight devices to share the same bus via hardware-selectable address pins A0, A1, and A2.

I/o Expanders Feature Summary

• Provides 16 configurable I/O pins that default to high-impedance inputs at power-up
• Features an open-drain interrupt output triggered by input state changes
• Includes Schmitt-trigger action and noise filters on SCL and SDA inputs for improved noise immunity
• Offers 5 V tolerant I/Os compatible with various logic families

I/o Expanders Applications

• ACPI power switches requiring additional control lines
• Sensor interface circuits needing expanded digital inputs
• Push button matrix scanning systems
• LED status indication and direct drive applications
• Fan control modules in embedded systems

I/o Expanders Procurement Notes

Verify the ordering suffix 'J' against the manufacturer's official documentation to confirm specific tape-and-reel packaging or variant details. Ensure the TSSOP24 package type matches the target PCB footprint requirements. Confirm the -40 °C to +85 °C temperature range aligns with the operational environment specifications before finalizing procurement orders.

I/o Expanders Selection Notes

Select this component when existing microcontroller GPIO resources are insufficient for the application design. It is suitable for designs requiring low standby current and 5 V tolerance on I/O lines while operating from lower supply voltages. Consider the interrupt functionality if event-driven input monitoring is preferred over continuous polling to reduce processor load.

I/o Expanders Part Context

The PCA9555 is part of Nexperia's family of I²C-bus I/O expanders designed to enhance system flexibility. It serves as a parallel port expander, allowing designers to minimize interconnections in complex embedded architectures. The device integrates internal power-on reset and latch-up protection exceeding 100 mA per JESD78 standards, ensuring robust operation in industrial environments.

I/o Expanders Replacement Considerations

The PCA9555 is pin-to-pin and I²C address compatible with the PCF8575. However, software modifications may be required due to enhanced features such as higher drive capability and different register behaviors. Verify register mapping compatibility before substituting other 16-bit I/O expanders.