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TMS570LS0232: MTTFd

Part Number: TMS570LS0232

Where can i find this parameter?

  • Hello,

    MTTFd (Mean time to dangerous failure) is used in ISO13849. 

    The metrics listed in our FMEDA is for IEC61508 and ISO26262. You can use those data to estimate the parameters for ISO 13849.

    IEC 61508 offers 4 Safety Integrity Levels (SIL) for safety related systems: SIL1, SIL2, SIL3, and SIL4. The SIL classification of safety related systems depends on the following parameters: 

    • Probability of Failure per hour  (PFH)
    • Safe Failure Fraction SFF)
    • Hardware Fault Tolerance (HFT)

    ISO 13849 offers 5 categories (Cat) and 5 performance levels (PL): CAT B, CAT 1,...CAT 4; PL a, PL b,... PL e

    Normally the following parameters are used in ISO 13849 when assigning CAT and PL level to a safety related system:

    • MTTFd : Mean Time to Dangerous Failure
    • DCavg: Average diagnostic coverage

    ISO 13849 uses MTTFd for quantifying channel safety, and PFH for quantifying safety of the complete safety related system. You can estimate the MTTFd as 1/PFH.

    Please refer to the spec of ISO 13849. 

  • I know ISO 13849 :).
    we are estimating these parameters for our PL application.

    Can you share your FMEDA, so we can estimate the MFFTd parameter for ISO 13849?

  • These documents are available on the safeTI forum, as they can only be accessed under the safeTI NDA.

    This page has links to all safety-related NDA documentation (requires safeTI NDA for access):

    Please contact with TI local sales or FAE if you don't have Safeti NDA.