SFFS272 September   2022 TPS7B81-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 HVSSOP Package
    2. 2.2 WSON Package
    3. 2.3 TO-252 Package
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 HVSSOP Package
    2. 4.2 WSON Package
    3. 4.3 TO-252 Package

2.2 WSON Package

This section provides functional safety failure in time (FIT) rates for the WSON package of the TPS7B81-Q1 based on two different industry-wide used reliability standards:

  • Table 2-3 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
  • Table 2-4 provides FIT rates based on the Siemens Norm SN 29500-2
Table 2-3 Component Failure Rates per IEC TR 62380 / ISO 26262 Part 11
FIT IEC TR 62380 / ISO 26262 FIT (Failures Per 109 Hours)
Total component FIT rate 8
Die FIT rate 6
Package FIT rate 2

The failure rate and mission profile information in Table 2-3 comes from the reliability data handbook IEC TR 62380 / ISO 26262 part 11:

  • Mission profile: Motor control from table 11
  • Power dissipation: 300 mW
  • Climate type: World-wide table 8
  • Package factor (lambda 3): Table 17b
  • Substrate material: FR4
  • EOS FIT rate assumed: 0 FIT
Table 2-4 Component Failure Rates per Siemens Norm SN 29500-2
Table Category Reference FIT Rate Reference Virtual TJ
4 Power amplifier and regulator ≤ 1 Watt – (LDO) 40 FIT 70°C

The reference FIT rate and reference virtual TJ (junction temperature) in Table 2-4 come from the Siemens Norm SN 29500-2 tables 1 through 5. Failure rates under operating conditions are calculated from the reference failure rate and virtual junction temperature using conversion information in SN 29500-2 section 4.