SFFS422 May   2022

 

  1.   Trademarks
  2.   2
  3. 1Scope
  4. 2Related Documents
  5. 3Related Standards and Acronyms
  6. 4Concept Overview
    1. 4.1 System Block Diagram
    2. 4.2 System Specifications
    3. 4.3 Conditions of use: Assumptions
      1. 4.3.1 Generic Assumptions
      2. 4.3.2 Specific Assumptions
    4. 4.4 Safe Torque Off Implementation
      1. 4.4.1 Subsystem Elements
      2. 4.4.2 STO Safe Subsystem States and Timing Diagram
      3. 4.4.3 STO_1 Subsystem
      4. 4.4.4 STO_2 Subsystem
      5. 4.4.5 MCU (SIL 1) Diagnostic Coverage
      6. 4.4.6 STO_FB Subsystem
      7. 4.4.7 Information on ICs
        1. 4.4.7.1 Isolated 24-V Input Receiver
        2. 4.4.7.2 Load Switch: TPS22919
        3. 4.4.7.3 High-Side Switch: TPS27S100
        4. 4.4.7.4 Isolated Gate Driver: ISO5852S (ISO5452)
    5. 4.5 Safe State
  7. 5Concept FMEA
    1. 5.1 System FMEA
  8. 6References

5 Concept FMEA

The concept FMEA was based on IEC 61800-5-2: 2016 paragraph D.3 Fault Models shown in the following list. The concept GMEA also considers 61508-2 table A1, discrete hardware DC fault models for drift and oscillation.

  • D.3.8 Resistors: The requirements of ISO 13849-2:2012, Table D.14 apply.
  • D.3.11 Capacitors: The requirements of ISO 13849-2:2012, Table D.17 apply.
  • D.3.12 Discrete semiconductors: For example diodes, Zener diodes, transistors, triacs, GTO thyristors, IGBTs, voltage regulators, quartz crystal, phototransistors, light-emitting diodes [LEDs]. The requirements of ISO 13849-2:2012, Table D.18 apply.
  • D.3.13 Signal Isolation components: The requirements of IEC 61800-5-2 Table D.5 apply.
  • D.3.14 Non-programmable integrated circuits (IC): The requirements of IEC 61800-5-2: 2016 Table D.6 applies. In this standard, ICs with less than 1 000 gates, less than 24 pins, or both, operational amplifiers, shift registers and hybrid modules are considered to be non-complex. This definition is arbitrary.
  • D.3.15 Programmable ICs, complex ICs, or ICs that are both programmable and complex: The requirements of Table D.7 apply. In this standard, an IC is considered to be complex if it consists of more than 1 000 gates, more than 24 pins, or both 1 000 gates and more than 24 pins. This definition is arbitrary. The analysis should identify additional faults which should be considered if they influence the operation of the safety sub-function.

This FMEA considers comparators, logic gates, and load switches (less than 24-pins) type A per IEC 61800-5-2 D3.14, ISO1211 and ISO5852S (or ISO5452) are part of D3.13 and D.3.14.