The MCP23017T-E/SS is a 16-bit input/output expander with an I2C interface designed and manufactured by Microchip Technology. It is an expansion device that operates as an I2C slave device that can be programmed to provide additional input/output lines to a variety of applications. The device has two I2C serial clock (SCL) and serial data (SDA) pins, a configurable Reset input and an interrupt output defined with the chip's internal logic. The features of the device include 16-bit parallel I/O (input/output) ports, a common interrupt line for communication between intermunicipal ports, an open drain Keypad Scan port and an external Reset pin. Its various other features include programmable I/O Direction Control to set input/output logic levels, internal pull-up resistors and programmable interrupt capabilities to detect changes on the I/O pins. The device is ideal for applications like keypad controls, battery operated remote controls, LED and LCD display interfacing, as well as motor control applications.