SBAS925A August 2018 – November 2018 ADS1119
The ADS1119 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 ADS1119 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.