I²C, often called I ‘two’ C, stands for the Inter-Integrated Circuit protocol. I²C was developed in 1982 by Philips Semiconductor (now NXP Semiconductor) as a low-speed communication protocol for connecting controller devices such as microcontrollers and processors with target devices such as data converters and other peripheral devices. Since 2006, implementing the I²C protocol does not require a license, and many semiconductor device companies, including TI, have introduced I²C-compatible devices.

I²C is a widely-used protocol for many reasons. The protocol requires only two lines for communications. Like other serial communication protocols, there is a serial data line and a serial clock line. I²C can connect to multiple devices on the bus with only the two lines. The controller device can communicate with any target device through a unique I²C address sent through the serial data line. I²C is simple and economical for device manufacturers to implement.