PCA9554PW,118

Overview

The PCA9554PW,118 is an 8-bit I2C and SMBus I/O expander designed to provide remote I/O expansion for microcontrollers via the two-line bidirectional bus. It features an active-low interrupt output that notifies the host controller of input state changes, eliminating the need for constant polling. Each of the eight I/O pins can be independently configured as an input or output, and the device includes a polarity inversion register for flexible logic management.

Why Choose This Part

The device supports a wide operating voltage range from 2.3V to 5.5V and features 5V tolerant I/Os, making it ideal for mixed-voltage systems. It includes an internal power-on reset and a noise filter on the SCL and SDA inputs to ensure robust operation in noisy environments. With a low standby current of 550uA and a glitch-free power-up sequence, it is well-suited for battery-powered applications.

Applications

Getting Started

To integrate this device, connect the SCL and SDA lines to your microcontroller's I2C bus with appropriate pull-up resistors and configure the three hardware address pins (A0, A1, A2) to set the unique I2C address. Use standard I2C write commands to the Configuration register (0x03) to set pin directions and read the Input Port register (0x00) to capture pin states. Engineers can use the NXP OM13082 logic evaluation board or similar I2C development tools for rapid prototyping.

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