SFFS372 February   2022 TPS74801-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 VQFN Package
    2. 2.2 VSON Package
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 VQFN Package
    2. 4.2 VSON Package

VQFN Package

This section provides functional safety failure in time (FIT) rates for the VQFN package of the TPS74801-Q1 based on two different industry-wide used reliability standards:

  • Table 2-1 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
  • Table 2-2 provides FIT rates based on the Siemens Norm SN 29500-2
Table 2-1 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 21
Die FIT rate 5
Package FIT rate 16

The failure rate and mission profile information in Table 2-1 comes from the reliability data handbook IEC TR 62380 / ISO 26262 part 11:

  • Mission profile: Motor control from table 11
  • Power dissipation: 1000 mW
  • Climate type: World-wide table 8
  • Package factor (lambda 3): Table 17b
  • Substrate material: FR4
  • EOS FIT rate assumed: 0 FIT
Table 2-2 Component Failure Rates per Siemens Norm SN 29500-2
Table Category Reference FIT Rate Reference Virtual TJ
4 Power amplifier and regulator 40 FIT 70°C

The reference FIT rate and reference virtual TJ (junction temperature) in Table 2-2 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.