All trademarks are the property of their respective owners.
This document contains information for DRV8245-Q1 to aid in a functional safety system design. This document covers all the device package and interface variants as listed below:
Figure 1-1 shows the HW device variant's functional block diagram for reference.
Figure 1-2 shows the SPI "S" device variant's functional block diagram for reference.
Figure 1-3 shows the SPI "P" device variant's functional block diagram for reference.
DRV8245-Q1 was developed using a quality-managed development process, but was not developed in accordance with the IEC 61508 or ISO 26262 standards.
ADVANCE INFORMATION for preproduction products; subject to change without notice.
This section provides Functional Safety Failure In Time (FIT) rates for DRV8245-Q1 based on two different industry-wide used reliability standards:
FIT IEC TR 62380 / ISO 26262 | FIT (Failures Per 109 Hours) | ||||
---|---|---|---|---|---|
HW variant in HTSSOP package | SPI "S" variant in HTSSOP package | SPI "P" variant in HTSSOP package | HW variant in VQFN-HR package | SPI "S" variant in VQFN-HR package | |
Total Component FIT Rate | 27 | 27 | 27 | 25 | 25 |
Die FIT Rate | 8 | 8 | 8 | 13 | 13 |
Package FIT Rate | 19 | 19 | 19 | 12 | 12 |
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 Digital, analog / mixed | 25 FIT | 55°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 DRV8245-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 (%) |
---|---|
Output is stuck LOW when commanded OFF (GND short) | 14%(2) |
Output is stuck HIGH when commanded OFF (VM short) | 14%(2) |
Output is stuck OFF when commanded LOW (Open) | 8%(2) |
Output is stuck OFF when commanded HIGH (Open) | 8%(2) |
Output ON resistance too high when commanded LOW | 12%(2) |
Output ON resistance too high when commanded HIGH | 18%(2) |
Low side slew rate too fast or too slow (high-side recirculation) | 5%(2) |
High side slew rate too fast or too slow (low-side recirculation) | 5%(2) |
Dead-time is too short | 1%(2) |
Current sense feedback incorrect | 3% |
ITRIP current regulation incorrect | 3% |
Incorrect communication (SPI variant)/ configuration interpretation (HW variant) | 4%(1) |
Incorrect input interpretation (nSLEEP, DRVOFF, EN/IN1, PH/IN2) | 4%(1) |
Incorrect nFAULT assertion | 1% |