General description
The TJA1021 is the interface between the Local Interconnect Network (LIN) master/slave protocol controller and the physical bus in a LIN. It is primarily intended for in-vehicle sub-networks using baud rates from 1 kBd up to 20 kBd and is LIN 2.1/SAE J2602 compliant. The TJA1021 is pin-to-pin compatible with the TJA1020 with an improved ElectroStatic Discharge (ESD) specification.
The transmit data stream of the protocol controller at the transmit data input (TXD) is converted by the TJA1021 into a bus signal with optimized slew rate and wave shaping to minimize ElectroMagnetic Emission (EME). The LIN bus output pin is pulled HIGH via an internal termination resistor. For a master application, an external resistor in series with a diode should be connected between pin INH or pin VBATand pin LIN. The receiver detects the data stream at the LIN bus input pin and transfers it via pin RXD to the microcontroller.
In Sleep mode, the power consumption of the TJA1021 is very low. In failure modes, the power consumption is reduced to a minimum.

FEATUREs and benefits
2.1 General
 LIN 2.1/SAE J2602 compliant
 Baud rate up to 20 kBd
 Very low ElectroMagnetic Emission (EME)
 High ElectroMagnetic Immunity (EMI)
 Passive behavior in unpowered state
 Input levels compatible with 3.3 V and 5 V devices
 Integrated termination resistor for LIN slave applications
 Wake-up source recognition (local or remote)
 Supports K-line like functions
 Pin-to-pin compatible with TJA1020
2.2 Low power management
 Very low current consumption in Sleep mode with local and remote wake-up
2.3 Protection mechanisms
 High ESD robustness: 6 kV according to IEC 61000-4-2 for pins LIN, VBATand WAKE_N
 Transmit data (TXD) dominant time-out function
 Bus terminal and battery pin protected against transients in the automotive environment (ISO 7637)
 Bus terminal short-circuit proof to battery and ground 
    Thermally protected