The PCA9554D,118 Interface - I/O Expanders 8-BIT I2C FM TP GPIO INT PU is an integrated circuit (IC) manufactured by NXP. It is an I2C pin and port expander that can be used to connect multiple devices to a microcontroller through a single port. The device has eight bidirectional I/O lines, each of which can be individually programmed as either an output or an input. The device also features an interrupt line (INT), and a pull-up resistor (PU),resistor allowing for easy and flexible implementation to systems. It is low-power, 8-bit I2C bus and SMBus compatible, able to operate over a wide range of power supply voltages from 1.65V to 5.5V. This component is ideal for applications such as industrial automation, medical monitoring, and home automation.