LM5156, LM5156-Q1, LM51561, LM51561-Q1, LM5156H, LM5156H-Q1, LM51561H, LM51561H-Q1, and LM34966-Q1 Functional Safety FIT Rate and FMD
1 Overview
This document contains information for LM5156, LM5156-Q1, LM51561, LM51561-Q1 (WSON), LM5156H, LM5156H-Q1, LM51561H, LM51561H-Q1, and LM34966-Q1 (HTSSOP) to aid in a functional safety system design. Information provided are:
- Functional Safety Failure In Time (FIT) rates of the semiconductor component estimated by the application of industry reliability standards
- Component failure modes and their distribution (FMD) based on the primary function of the device
Figure 1-1 and Figure 1-2 show the device functional block diagrams for reference.
Figure 1-1 Functional Block Diagram
(LM5156xH, LM5156xH-Q1)
Figure 1-2 Functional Block Diagram (LM34966-Q1)The LM5156, LM5156-Q1, LM51561, LM51561-Q1, LM5156H, LM5156H-Q1, LM51561H, LM51561H-Q1, and LM34966-Q1 were developed using a quality-managed development process, but were not developed in accordance with the IEC 61508 or ISO 26262 standards.
2 Functional Safety Failure In Time (FIT) Rates
This section provides Functional Safety Failure In Time (FIT) rates for LM5156, LM5156-Q1, LM51561, LM51561-Q1 (package of WSON) 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
| FIT IEC TR 62380 / ISO 26262 | FIT (Failures Per 109 Hours) |
|---|---|
| Total Component FIT Rate | 6 |
| Die FIT Rate | 3 |
| Package FIT Rate | 3 |
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
- Power dissipation: 250 mW
- Climate type: World-wide Table 8
- Package factor (lambda 3): Table 17b
- Substrate Material: FR4
- EOS FIT rate assumed: 0 FIT
| Table | Category | Reference FIT Rate | Reference Virtual TJ |
|---|---|---|---|
| 5 | CMOS/BICMOS ASICs Analog & 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.
3 Functional Safety Failure In Time (FIT) Rates
This section provides Functional Safety Failure In Time (FIT) rates for LM5156H, LM5156H-Q1, LM51561H, LM51561H-Q1, and LM34966-Q1 (package of HTSSOP) based on two different industry-wide used reliability standards:
- Table 3-1 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
- Table 3-2 provides FIT rates based on the Siemens Norm SN 29500-2
| FIT IEC TR 62380 / ISO 26262 | FIT (Failures Per 109 Hours) |
|---|---|
| Total Component FIT Rate | 12 |
| Die FIT Rate | 4 |
| Package FIT Rate | 8 |
The failure rate and mission profile information in Table 3-1 comes from the Reliability data handbook IEC TR 62380 / ISO 26262 part 11:
- Mission Profile: Motor Control from Table 11
- Power dissipation: 250 mW
- Climate type: World-wide Table 8
- Package factor (lambda 3): Table 17b
- Substrate Material: FR4
- EOS FIT rate assumed: 0 FIT
| Table | Category | Reference FIT Rate | Reference Virtual TJ |
|---|---|---|---|
| 5 | CMOS/BICMOS ASICs Analog & Mixed HV >50V supply | 30 FIT | 75°C |
The Reference FIT Rate and Reference Virtual TJ (junction temperature) in Table 3-2 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.
