SLVAEV2 June   2020 DRV8873-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 DRV8873H-Q1 (HW variant)
    2. 4.2 DRV8873S-Q1 (SPI variant)

Failure Mode Distribution (FMD)

The failure mode distribution estimation for DRV8873-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.

Table 3-1 Die Failure Modes and Distribution
Die Failure ModesFailure Mode Distribution (%)
OUTx is stuck LOW when commanded OFF 14%
OUTx is stuck OFF when commanded LOW 8%
OUTx ON resistance too high when commanded LOW 12%
Low side slew rate too fast or too slow 5%
OUTx is stuck HIGH when commanded OFF 14%
OUTx is stuck OFF when commanded HIGH 8%
OUTx ON resistance too high when commanded HIGH 17%
High side slew rate too fast or too slow 5%
Dead-time is too short 1%
Current sense feedback incorrect 3%
ITRIP current regulation incorrect 3%
Incorrect communication or fault indication 10%