SFFS243 august   2021 DRV8143-Q1

 

  1.   1
  2.   Trademarks
  3. 1Overview
  4. 2Functional Safety Failure In Time (FIT) Rates
  5. 3Failure Mode Distribution (FMD)
  6. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 SPI "P" variant in HVSSOP package
    2. 4.2 SPI "S" variant in VQFN-HR package
    3. 4.3 HW variant in VQFN-HR package
  7. 5Revision History

Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) of the pins for each of the device variants of DRV8143-Q1 as listed below.

  1. SPI "P" variant in HVSSOP package
  2. HW variant in VQFN-HR package
  3. SPI "S" variant in VQFN-HR package

The failure modes covered in this document include the typical pin-by-pin failure scenarios:

  • Pin short-circuited to Ground
  • Pin open-circuited
  • Pin short-circuited to an adjacent pin
  • Pin short-circuited to supply

The analysis also indicates how these pin conditions can affect the device as per the failure effects classification in Table 4-1.

Table 4-1 TI Classification of Failure Effects
ClassFailure Effects
APotential device damage that affects functionality
BNo device damage, but loss of functionality
CNo device damage, but performance degradation
DNo device damage, no impact to functionality or performance

Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:

GUID-20201008-CA0I-K0T5-5PXH-1VC7XWMHBT1H-low.svg Figure 4-1 Using dual DRV814x-Q1 as a Full Bridge configuration with low-side recirculation
  • Test conditions:
    • VVM = 13.5 V, TAmbient = 25°C , SPI "P" variant: VVDD = 5 V
  • SPI "S" and "P" variant:
    • DRVOFF ( pins combined) and IN pins controlled by controller
    • IPROPI (pins combined) monitored by controller, nFAULT (pins combined) monitoring optional
    • Configurations: SPI_IN unlocked with
      • DRVOFF_SEL = 1'b0 (Pin and register control for redundant shutoff)
      • IN_SEL for switching half bridge device = 1'b1 (Pin only control for PWM)
      • IN_SEL for non-switching half bridge device = 1'b0 (Register only control)
  • HW variant:
    • nSLEEP, DRVOFF, EN/IN1, PH/IN2 pins controlled by controller
    • nFAULT and IPROPI pins monitored by controller
    • NC pin floating