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. Master applications require an external pullup resistor (1 k) plus a series diode per the LIN specification.

In sleep mode, the TPIC1021A requires low quiescent current even though the wake-up circuits remain active, allowing for remote wake up via the LIN bus or local wake up via the NWake or EN pins.

The TPIC1021A has been designed for operation in the harsh automotive environment. The device can handle LIN bus voltage swings from 40 V down to ground and survive –40 V. The device also prevents back-feed current through LIN to the supply input, in case of a ground shift or supply voltage disconnection. It also features undervoltage, overtemperature, and loss-of-ground protection. In the event of a fault condition, the output is immediately switched off and remains off until the fault condition is removed.

• LIN Physical Layer Specification Revision 2.0 Compliant and Conforms to SAEJ2602 Recommended Practice for LIN
• LIN Bus Speed up to 20-kbps LIN Specified Maximum
• Sleep Mode: Ultralow Current Consumption, Allows Wake-Up Events From LIN Bus, Wake-Up Input (External Switch), or Host MCU
• High-Speed Receive Capable
• ESD Protection to ±12 kV (Human-Body Model) on LIN Pin
• LIN Pin Handles Voltage From –40 V to 40 V
• Survives Transient Damage in Automotive Environment (ISO 7637)
• Extended Operation With Supply From 7 V to 27 V DC (LIN Specification 7 V to 18 V)
• Interfaces to MCU With 5-V or 3.3-V I/O Pins
• Dominant State Timeout Protection
• Wake-Up Request on RXD Pin
• Control of External Voltage Regulator (INH Pin)
• Integrated Pullup Resistor and Series Diode for LIN Slave Applications
• Low Electromagnetic Emission (EME), High Electromagnetic Immunity (EMI)
• Bus Terminal Short Circuit Protected for Short to Battery or Short to Ground
• Thermally Protected
• Ground Disconnection Fail Safe at System Level
• Ground Shift Operation at System Level
• Unpowered Node Does Not Disturb the Network
• Supports ISO9141 (K-Line)-Like Functions