SLLA535 December   2022 TLIN1431-Q1

 

  1. 1Introduction
    1.     Trademarks
  2. 2TLIN1431x-Q1 Hardware Component Functional Safety Capability
  3. 3Development Process for Management of Systematic Faults
    1. 3.1 TI New-Product Development Process
    2. 3.2 TI Functional Safety Development Process
  4. 4TLIN1431x-Q1 Component Overview
    1. 4.1 Targeted Applications
    2. 4.2 Hardware Component Functional Safety Concept
    3. 4.3 Functional Safety Constraints and Assumptions
  5. 5Description of Hardware Component Parts
    1. 5.1 LIN Transceiver
    2. 5.2 Digital Core
    3. 5.3 Power Control IP
    4. 5.4 Digital Input/Output Pins and High-side Switch
  6. 6TLIN1431x-Q1 Management of Random Faults
    1. 6.1 Fault Reporting
    2. 6.2 Functional Safety Mechanism Categories
    3. 6.3 Description of Functional Safety Mechanisms
      1. 6.3.1 LIN Bus and Communication
        1. 6.3.1.1 SM-1: LIN TXD Pin Dominant State Timeout
        2. 6.3.1.2 SM-2: LIN Bus Stuck Dominant System Fault: False Wake Up Lockout
        3. 6.3.1.3 SM-3: LIN Bus Short Circuit Limiter
        4. 6.3.1.4 SM-20: LIN Internal pull-up to VSUP
        5. 6.3.1.5 SM-22: LIN Protocol
      2. 6.3.2 Voltage Rail Monitoring
        1. 6.3.2.1 SM-4: VCC and Transceiver Thermal Shutdown
        2. 6.3.2.2 SM-5: VCC Under-voltage
        3. 6.3.2.3 SM-6: VCC Over-voltage
        4. 6.3.2.4 SM-7: VCC Short to Ground
        5. 6.3.2.5 SM-8: VSUP Under-voltage
      3. 6.3.3 Processor Communication
        1. 6.3.3.1 SM-9 and SM-10: Watchdog
          1. 6.3.3.1.1 SM-9: Standby Mode Long Window Timeout Watchdog
          2. 6.3.3.1.2 SM-10: Normal Mode Watchdog
        2. 6.3.3.2 SM-11: SPI CRC
        3. 6.3.3.3 SM-12: SPI Communication Error; SPIERR
        4. 6.3.3.4 SM-13: Scratchpad Write/Read Register
        5. 6.3.3.5 SM-14: Sleep Wake Error Timer; tINACT_FS
      4. 6.3.4 Digital Input/Output Pins and High-side Switch
        1. 6.3.4.1 SM-15: CLK internal pull-up to VINT
        2. 6.3.4.2 SM-16: SDI internal pull-up to VINT
        3. 6.3.4.3 SM-17: nCS Internal pull-up to VINT
        4. 6.3.4.4 SM-18: DIV_ON Internal pull-down to GND
        5. 6.3.4.5 SM-19: TXD Internal pull-up to VINT
        6. 6.3.4.6 SM-21: nRST Internal pull-up to VINT
        7. 6.3.4.7 SM-23: HSS Over Current Detect
        8. 6.3.4.8 SM-24: HSS Open Load Detect
          1.        A Summary of Recommended Functional Safety Mechanism Usage
            1.         B Distributed Developments
              1.          B.1 How the Functional Safety Lifecycle Applies to TI Functional Safety Products
              2.          B.2 Activities Performed by Texas Instruments
              3.          B.3 Information Provided
                1.           C Revision History

5.4 Digital Input/Output Pins and High-side Switch

The TLIN1431x-Q1 has 8 digital I/O pins, four of which are used to implement the SPI communications or watchdog functionality, two are utilized for the TXD and RXD signals for the LIN, and the last two are used for nRST and nINT interrupt functionality. Five of these input pins have integrated pull-up resistors that weakly bias them. The TLIN1431x-Q1 provides a reverse polarity protected resistor divider connected to VBAT with fast response times. The divider ratio is based upon the LDO output voltage value. The voltage divider is activated by a high on the DIV_ON pin.

The TLIN1431x-Q1 provides a high-side switch supporting up to a 100 mA load. The switch supports open load detection and over current detection. In SPI mode, it can be programmed to support a PWM. The HSS can be configured to use one of two timers that allows it to work with the WAKE pin. This supports cyclic sensing for sleep mode thus reducing sleep mode current.

The following tests can be applied as functional safety mechanisms for this module (to provide diagnostic coverage on a specific function):