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

3.2 TI Functional Safety Development Process

The TI functional safety development flow derives from ISO 26262 and IEC 61508 a set of requirements and methodologies to be applied to semiconductor development. This flow is combined with TI's standard new product development process to develop TI functional safety components. The details of this functional safety development flow are described in the TI internal specification - SafeTI Functional Safety Hardware.

Key elements of the TI functional safety-development flow are as follows:

  • Assumptions on system level design, functional safety concept, and requirements based on TI's experience with components in functional safety applications
  • Qualitative and quantitative functional safety analysis techniques including analysis of silicon failure modes and application of functional safety mechanisms
  • Base FIT rate estimation based on multiple industry standards and TI manufacturing data
  • Documentation of functional safety work products during the component development
  • Integration of lessons learned through multiple functional safety component developments, functional safety standard working groups, and the expertise of TI customers

Table 3-1 lists these functional safety development activities which are overlaid atop the standard development flow in Figure 3-1.

Refer to Appendix B for more information about which functional safety lifecycle activities TI performs.

The customer facing work products derived from this TI functional safety process are applicable to many other functional safety standards beyond ISO 26262 and IEC 61508.

Table 3-1 Functional Safety Activities Overlaid on top of TI's Standard Development Process
Assess Plan Create Validate Sustain and End-of-Life
Determine if functional safety process execution is required Define component target SIL/ASIL capability Develop component level functional safety requirements Validate functional safety design in silicon Document any reported issues (as needed)
Nominate a functional safety manager Generate functional safety plan Include functional safety requirements in design specification Characterize the functional safety design Perform incident reporting of sustaining operations (as needed)
End of Phase Audit Verify the functional safety plan Verify the design specification Qualify the functional safety design (per AEC-Q100) Update work products (as needed)
Initiate functional safety case Start functional safety design Finalize functional safety case
Analyze target applications to generate system level functional safety assumptions Perform qualitative analysis of design (i.e. failure mode analysis) Perform assessment of project
End of Phase Audit Verify the qualitative analysis Release functional safety manual
Verify the functional safety design Release functional safety analysis report
Perform quantitative analysis of design (i.e. FMEDA) Release functional safety report
Verify the quantitative analysis End of Phase Audit
Iterate functional safety design as necessary
End of Phase Audit