SFFS112 April 2021 TPS25850-Q1 , TPS25858-Q1

2 Functional Safety Failure In Time (FIT) Rates

This section provides Functional Safety Failure In Time (FIT) rates for TPS25850-Q1 and TPS25858-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 for TPS25850-Q1

Table 2-2 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11 for TPS25858-Q1

Table 2-3 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 for TPS25850-Q1

FIT IEC TR 62380 / ISO 26262-11 (1)	FIT (Failures Per 10⁹ Hours)
Total FIT Rate	45
Die FIT Rate	17
Package FIT Rate	28

Table 2-2 Component Failure Rates per IEC TR 62380 / ISO 26262 Part 11 for TPS25858-Q1

FIT IEC TR 62380 / ISO 26262-11 (1)	FIT (Failures Per 10⁹ Hours)
Total FIT Rate	37
Die FIT Rate	11
Package FIT Rate	26

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

Mission Profile: Motor Control from Table 11
Power dissipation:
- TPS25850-Q1: 1700 mW
- TPS25858-Q1: 1300 mW
Climate type: World-wide Table 8
Package factor (lambda 3): Table 17b
Substrate Material: FR4
EOS FIT rate assumed: 0 FIT

Table 2-3 Component Failure Rates per Siemens Norm SN 29500-2

Table	Category	Reference FIT Rate	Reference Virtual T_J
5	Digital, Analog, Mixed	25	55°C

The Reference FIT Rate and Reference Virtual T_J (junction temperature) in Table 2-3 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.