SFFSAY3 January   2026 F29H850TU , F29H859TU-Q1 , TMCS1123 , TMCS1123-Q1 , TPS650362-Q1 , TPS650365-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Background
    2. 1.2 HW/SW FuSa Analysis Process
      1. 1.2.1 Item Definition
      2. 1.2.2 Functional Safety Goal
      3. 1.2.3 Functional Safety Concept
      4. 1.2.4 Technical Safety Concept
      5. 1.2.5 HW/SW Safety Requirement
      6. 1.2.6 Dependent‑failure Analysis
    3. 1.3 TI Collaterals
      1. 1.3.1 TI Components Category
      2. 1.3.2 FuSa Collaterals for Safety MCU
  5. 2FuSa Concepts of OBC System
    1. 2.1 Item Definition
      1. 2.1.1 Item Functions
      2. 2.1.2 System Boundaries
      3. 2.1.3 External Interfaces
      4. 2.1.4 Operation Modes
    2. 2.2 Functional Safety Goal
    3. 2.3 Functional Safety Concept
    4. 2.4 Technical Safety Concept
    5. 2.5 HW/SW Safety Requirement
    6. 2.6 Dependent‑Failure Analysis
  6. 3FuSa Components of OBC System
    1. 3.1 Components Overview
    2. 3.2 Microcontroller
      1. 3.2.1 CPU
      2. 3.2.2 ADC Sample
      3. 3.2.3 PWM Generation
      4. 3.2.4 CMPSS
      5. 3.2.5 Data Transmission
      6. 3.2.6 Fault Signal Monitor and Safe State Control
    3. 3.3 Power Management IC
      1. 3.3.1 MCU Monitor
      2. 3.3.2 Shutdown Sequence
      3. 3.3.3 Power Supply
    4. 3.4 System Basis Chips
      1. 3.4.1 CAN Communication
      2. 3.4.2 Supply Voltage Rail Monitoring
      3. 3.4.3 SPI/Processor Communication
      4. 3.4.4 Device Internal EEPROM
    5. 3.5 Power Supply and Supervisor
    6. 3.6 Gate Driver
    7. 3.7 Voltage Sensor
    8. 3.8 Current Sensor
    9. 3.9 Temperature Sensor
  7. 4Summary
  8. 5References

2.6 Dependent‑Failure Analysis

DFA should be performed to identify the cascaded failures and common-cause failures that could influence redundancy. Additional TSRs for independence requirement are recognized by DFA analysis. Generally, DFA analysis confirms:

  • Physical separation. Redundant components have sufficient physical separation, and different routing for redundant signal paths, and thermal isolation between critical components.
  • Diversity. Different technologies are used for redundant functions, and different suppliers for critical components, and different implementation methods for hardware and software protection.
  • Independence. Independent power supplies for redundant circuits, and independent processing for redundant functions, and independent activation paths for safety mechanisms.

For example, if the bias supply of MCU is short-circuited to ground, the plausibility check cannot detect the fault, and software-related safety mechanisms also lose its function. In this case, voltage monitoring is the critical safety mechanism to verify the OBC enters safe state.