Driving I2C-bus signals over twisted pair cables

The availability of powerful I²C buffers that drive I/Os on both sides to a nominal ground or 'zero offset' logic level allows the removal of noise introduced into one section of a larger bus system. That 'regeneration' of clean I²C signals enables building long I²C-buses by combining together relatively short bus sections. Conventional twisted pair communication cabling with its convenient connectors and a modular I²C system approach, make large system assembly easy. Each drop point or node can be individually selected for bidirectional data communication with the Master just by using normal I²C software addressing. As an example, this paper describes a system for control of LED lighting displays.