SFFS223A March 2022 – June 2025 UCC27531-Q1

2 Functional Safety Failure In Time (FIT) Rates

This section provides functional safety failure in time (FIT) rates for UCC27531-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	Power Dissipation (mW)	FIT (Failures Per 10⁹ Hours)
Total component FIT rate	15	5
Total component FIT rate	150	8
Die FIT rate	15	3
Die FIT rate	150	6
Package FIT rate	15	2
Package FIT rate	150	2

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 or figure 16
Power dissipation: 15mW, 150mW
Climate type: World-wide table 8 or figure 13
Package factor (lambda 3): Table 17b or figure 15
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 T_J
5	CMOS, BICMOS Digital, analog, or mixed	20 FIT	55°C

The reference FIT rate and reference virtual T_J (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.