SFFSA03 September   2024 LM70840 , LM70860 , LM70880

 

  1.   1
  2.   Trademarks
  3. 1Overview
  4. 2Functional Safety Failure In Time (FIT) Rates
  5. 3Failure Mode Distribution (FMD)
  6. 4Pin Failure Mode Analysis (Pin FMA)

2 Functional Safety Failure In Time (FIT) Rates

This section provides functional safety failure in time (FIT) rates for LM70880, LM70860, and LM70840 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)
LM70880 LM70860 LM70840
Total component FIT rate 34 29 26
Die FIT rate 11 7 5
Package FIT rate 23 22 21

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
  • LM70880 power dissipation: 2.6W
  • LM70860 power dissipation: 1.75W
  • LM70840 power dissipation: 1.25W
  • 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 Device Reference FIT Rate Reference Virtual TJ
5 CMOS, BICMOS ASICs Analog and mixed HV > 50V supply LM70880 30 FIT 75°C
5 CMOS, BICMOS ASICs Analog and mixed HV > 50V supply LM70860 30 FIT 75°C
5 CMOS, BICMOS ASICs Analog and mixed HV > 50V supply LM70840 30 FIT 75°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.