8.5.1 I²C Interface

The ADS1219 uses an I²C-compatible (inter-integrated circuit) interface for serial communication. I²C is a 2-wire communication interface that allows communication of a master device with multiple slave devices on the same bus through the use of device addressing. Each slave device on an I²C bus must have a unique address. Communication on the I²C bus always takes place between two devices: one acting as the master and the other as the slave. Both the master and slave can receive and transmit data, but the slave can only read or write under the direction of the master. The ADS1219 always acts as an I²C slave device.

An I²C bus consists of two lines: SDA and SCL. SDA carries data and SCL provides the clock. Devices on the I²C bus drive the bus lines low by connecting the lines to ground; the devices never drive the bus lines high. Instead, the bus wires are pulled high by pullup resistors; thus, the bus wires are always high when a device is not driving the lines low. As a result of this configuration, two devices do not conflict. If two devices drive the bus simultaneously, there is no driver contention.

See the I²C-Bus Specification and User Manual from NXP Semiconductors™ for more details.