SFFS756 November   2023 SN74HCS20-Q1

 

  1.   1
  2.   Trademarks
  3. 1Overview
  4. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 D and PW Packages
  5. 3Failure Mode Distribution (FMD)
  6. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 D and PW Packages
  7. 5Revision History

3 Failure Mode Distribution (FMD)

The failure mode distribution estimation for SN74HCS20-Q1 in Table 3-1 comes from the combination of common failure modes listed in standards such as IEC 61508 and ISO 26262, the ratio of sub-circuit function size and complexity and from best engineering judgment.

The failure modes listed in this section reflect random failure events and do not include failures due to misuse or overstress.

Table 3-1 Die Failure Modes and Distribution
Die Failure ModesFailure Mode Distribution (%)
Output stuck-at fault

30%

Output open (HIZ)

25%

Output functional – out of specification timing or voltage

45%