SFFS029 December   2020 LM5127-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
  4. 3Failure Mode Distribution (FMD)

Failure Mode Distribution (FMD)

The failure mode distribution estimation for LM5127-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 Modes Failure Mode Distribution (%)
SW1/2/3 no output (any one or all three) 50%
SW1/2/3 output not in specification – voltage or timing (any one or all three) 35%
HO1/2/3 stuck on (any one or all three) 5%
DIS/BMOUT switch stuck on or off 5%
PGOOD1/2/3 – false trip or failure to trip (any one or all three) 5%