The TPIC1021 is the LIN (Local Interconnect Network) physical interface, which integrates the serial transceiver with wake up and protection features. The LIN bus is a single wire, bi-directional bus typically used for low-speed in-vehicle networks using baud rates between 2.4 kbps and 20 kbps. The LIN bus has two logical values: the dominant state (voltage near ground) represents a logic `0' and the recessive state (voltage near battery) and represents logic `1'. In the recessive state the LIN bus is pulled high by the TPIC1021's internal pull-up resistor (30k) and series diode, so no external pull-up components are required for slave applications. Master applications require an external pull-up resistor (1k) plus a series diode. The LIN Protocol output data stream on the TXD pin is converted by the TPIC1021 into the LIN bus signal through a current limited, wave-shaping low-side driver with control as outlined by the LIN Physical Layer Specification Revision 2.0. The receiver converts the data stream from the LIN bus and outputs the data stream via the RXD pin.