SLLA383A February   2018  – August 2022 SN65HVDA100-Q1 , SN65HVDA195-Q1 , TLIN1022-Q1 , TLIN1029-Q1 , TLIN2022-Q1 , TLIN2029-Q1 , TMS320F28P550SJ , TMS320F28P559SJ-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
    1. 1.1 LIN Specification Progression
    2. 1.2 Workflow Concept
  4. 2Network Architecture
    1. 2.1 General Layout of the LIN Bus
    2. 2.2 Serial Communication Principles
    3. 2.3 Commander-Responder Principle
    4. 2.4 Message Frame Format
  5. 3Physical Layer Requirements
    1. 3.1 Bus Signaling Fundamentals
    2. 3.2 Pullup Values
    3. 3.3 Threshold Values
    4. 3.4 Bit-Rate Tolerance and Timing Requirements
    5. 3.5 Synchronization and Bit Sampling
    6. 3.6 Duty Cycle
  6. 4Filtering, Distance Limitations, Nodes on Bus
    1. 4.1 EMI and Signal Conditioning
    2. 4.2 ESD and Transients
    3. 4.3 Distance and Node Limitations
  7. 5LIN Transceiver Special Functions
    1. 5.1 Low-Power Modes
      1. 5.1.1 Sleep Mode
      2. 5.1.2 Standby Mode
    2. 5.2 Wakeup
      1. 5.2.1 Pin Wakeup
      2. 5.2.2 LIN Wakeup
      3. 5.2.3 Dominant Timeout
  8. 6Advantages and Disadvantages
  9. 7Conclusion
  10. 8Revision History

2.1 General Layout of the LIN Bus

A LIN cluster is defined as a number of LIN nodes connected through a physical cable. There are two types of nodes in every cluster: one Commander node and up to 16 subsequent Responder nodes. This commander node is what manages the communication along the bus to each responder. More detail on the Commander-Responder principle is discussed in Section 2.3.

Figure 2-1 High-Level LIN Transceiver in Network

The idea of LIN is to be a simple, yet cost-effective communication interface. This is why a dedicated communication controller is not implemented. Instead, a microcontroller is programmed with the LIN protocol and used to drive the communication to the transceiver through the serial interface. This interface is named Serial Communication Interface (SCI) and it has replaced UART in most LIN applications. Both are typical of most microcontrollers, which allow less work on the back end to install.

The LIN bus transmission only requires one wire, and a slower communication speed is used in order to properly handle any radiated emissions issues. All nodes are passively connected to the bus, and a pullup resistor is used to ensure the bus is at the supply voltage level when the nodes are in the off-state.