The TPIC1021A is the Local Interconnect Network (LIN) physical interface, which integrates the serial transceiver with wake-up and protection features. The LIN bus is a single-wire bidirectional bus typically used for low-speed in-vehicle networks using data rates between
2.4 kbps and 20 kbps. The LIN protocol output data stream on TXD is converted by the TPIC1021A into the LIN bus signal through a current-limited wave-shaping driver 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 RXD. The LIN bus has two states: dominant state (voltage near ground) and the recessive state (voltage near battery). In the recessive state, the LIN bus is pulled high by the TPIC1021A’s internal pullup resistor (30 k) and series diode, so no external pullup components are required for slave applications.