SNVA921C Functional safety information

SNVA921C January 2020 – March 2024 LMR33620-Q1 , LMR33630-Q1

2.2 LMR33620-Q1

This section provides Functional Safety Failure In Time (FIT) rates for the LMR33620-Q1 based on the following 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	16
Die FIT Rate	6
Package FIT Rate	12

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: 370 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 T_J
5	CMOS, BICMOS ASICS Analog and Mixed ≤ 50-V supply	25 FIT	55°C

The Reference FIT Rate and Reference Virtual T_J (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.