The MCP23009T-E/MG is an 8-bit general-purpose I/O expander that provides parallel I/O expansion for I2C bus applications. It operates over a wide voltage range of 1.8V to 5.5V and features a high-speed I2C interface supporting rates up to 3.4 MHz. The eight bidirectional I/O pins are 5.5V tolerant, default to inputs, and feature open-drain outputs capable of sinking up to 25 mA each. A single hardware address pin allows up to eight devices on the same bus, and a configurable interrupt output makes it ideal for monitoring remote digital signals in industrial controls, portable electronics, and server management.