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This document contains information for LM5127-Q1 (VQFN package) to aid in a functional safety system design. Information provided are:
Figure 1-1 shows the device functional block diagram for reference.
LM5127-Q1 was developed using a quality-managed development process, but was not developed in accordance with the IEC 61508 or ISO 26262 standards.
This section provides Functional Safety Failure In Time (FIT) rates for LM5127-Q1 based on two different industry-wide used reliability standards:
FIT IEC TR 62380 / ISO 26262 | FIT (Failures Per 109 Hours) |
---|---|
Total Component FIT Rate | 41 |
Die FIT Rate | 7 |
Package FIT Rate | 34 |
The failure rate and mission profile information in Table 2-1 comes from the Reliability data handbook IEC TR 62380 / ISO 26262 part 11:
Table | Category | Reference FIT Rate | Reference Virtual TJ |
---|---|---|---|
5 | CMOS/BICMOS ASICs Analog and Mixed HV >50V supply | 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.
The failure mode distribution estimation for LM5127-Q1 in Table 3-1 comes from the combination of common failure modes listed in standards such as IEC 61508 and ISO 26262, the ratio of sub-circuit function size and complexity and from best engineering judgment.
The failure modes listed in this section reflect random failure events and do not include failures due to misuse or overstress.
Die Failure Modes | Failure Mode Distribution (%) |
---|---|
SW1/2/3 no output (any one or all three) | 50% |
SW1/2/3 output not in specification – voltage or timing (any one or all three) | 35% |
HO1/2/3 stuck on (any one or all three) | 5% |
DIS/BMOUT switch stuck on or off | 5% |
PGOOD1/2/3 – false trip or failure to trip (any one or all three) | 5% |