SDAA370 May   2026 UCC34141

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 End-Equipment Traction Inverter
    2. 1.2 Why is Safety Needed in Inverter?
    3. 1.3 FuSa Development Flow
      1. 1.3.1 V-Model Development
      2. 1.3.2 Inverter Safety Lifecycle
  5. 2FuSa Requirements for Traction Inverter
    1. 2.1 Traction Inverter Structure and Function Introduction
    2. 2.2 FuSa Requirements Derivation Process
    3. 2.3 Safety Goal
    4. 2.4 FuSa Concept
      1. 2.4.1 FSC Design Architecture
      2. 2.4.2 Fault Tree Analysis
      3. 2.4.3 FuSa Requirement
    5. 2.5 Technical Safety Concepts
      1. 2.5.1 TSC Design Architecture
      2. 2.5.2 Failure Mode and Effect Analysis
      3. 2.5.3 Technical Safety Requirements
  6. 3Safety Design Implementation on Inverter
    1. 3.1 TI FuSa Product
    2. 3.2 How Does TSR Implement?
      1. 3.2.1 Position Sensor
      2. 3.2.2 MCU
      3. 3.2.3 Logic Circuit
      4. 3.2.4 Smart Isolated Gate Driver
    3. 3.3 Dependent Failure Consideration
    4. 3.4 Detailed FuSa Design Structure for Traction Inverter
    5. 3.5 Achieving FuSa Requirements with TI Safety Devices
      1. 3.5.1 MCU
      2. 3.5.2 Gate Driver
        1. 3.5.2.1 Gate Monitor Circuit and Over Current Protection
        2. 3.5.2.2 Other Safety Mechanisms in UCC5881-Q1
      3. 3.5.3 Isolated bias supply
        1. 3.5.3.1 Centralized LV Isolated Power Supply Architecture
        2. 3.5.3.2 Fully Distributed LV Isolated Power Supply Architecture
        3. 3.5.3.3 Semi-Distributed LV Isolated Power Supply Architecture
        4. 3.5.3.4 HV Isolated Bias Supply
        5. 3.5.3.5 TI's Design for Isolated Bias Supply in Traction Inverter
      4. 3.5.4 Power Management IC
        1. 3.5.4.1 Multiple Paths Power Rail with Protection and Independent Thermal Shut-Down
        2. 3.5.4.2 Power Rail Voltage Monitoring
        3. 3.5.4.3 MCU Fault Monitor and other Protection Mechanisms
      5. 3.5.5 Position Sensor
      6. 3.5.6 Current Sensor
      7. 3.5.7 Voltage Sensor
        1. 3.5.7.1 Isolated DC Voltage Sensing
        2. 3.5.7.2 Non-Isolated DC voltage sensing
      8. 3.5.8 Temperature Sensor
  7. 4Summary
  8. 5References

2.4 FuSa Concept

After establishing safety goals, a FuSa Concept (FSC) is developed, which contains safety requirements for sub-functional elements. ISO26262:2018 recommends safety analysis methods such as deductive analysis and inductive analysis to identify failures and transform them into safety requirements. In this chapter, FTA is taken, a typical deductive analysis method, to derive FuSa requirements from safety goals. Taking SG1-Avoid unintended accelerating torque than expected as an example, this document demonstrates the process of constructing an FTA to derive FSR.

FTA is a top-down deductive analysis method that uses logical reasoning to identify all possible causes and combinations of system failures. The method employs Boolean logic to describe cause-and-effect relationships between events. All the possible causes that can directly lead to the top event can be identified through an FTA. This is where safety requirements are established for the basic events or gates, constituting the derivation process for FSRs.

The FTA methodology allows users to systematically break down the high-level safety goal into more specific functional requirements that address individual failure modes. By analyzing the logical combinations of events that can lead to unintended acceleration torque, critical areas requiring safety mechanisms can be identified and appropriate functional requirements to mitigate these risks can be established.