SFFS163 May   2021 DRV8871-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)

Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the DRV8871-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:

  • Pin short-circuited to Ground (see Table 4-2)
  • Pin open-circuited (see Table 4-3)
  • Pin short-circuited to an adjacent pin (see Table 4-4)
  • Pin short-circuited to supply (see Table 4-5)

Table 4-2 through Table 4-5 also indicate 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

Figure 4-1 shows the DRV8871-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the DRV8871-Q1 data sheet.

GUID-9D464C64-D215-4D87-B910-938287162FFB-low.gif Figure 4-1 Pin Diagram

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

  • The device is used with external components consistent with the values described in the external component table of the datasheet.
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
GND1Intended operationD
IN22OUTx driver control will be lostB
IN13OUTx driver control will be lostB
ILIM4 Current regulation capability will be lostB
VM5Device will not power upB
OUT16OUTx HiZB
PGND7Intended operationB
OUT28OUTx HiZB
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
GND1Device will not power upB
IN22OUTx driver control will be lostB
IN13OUTx driver control will be lostB
ILIM4Current regulation capability will be lostB
VM5Device will not power upB
OUT16OUT1 driver control will be lostB
PGND7OUT1 and OUT2 driver control will be lostB
OUT28OUT2 driver control will be lostB
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin NamePin No.Shorted toDescription of Potential Failure Effect(s)Failure Effect Class
GND1IN2OUTx driver control will be lostB
IN22IN1OUTx driver control will be lostB
IN13ILIMOUTx driver control will be lost, current regulation capability will be lostB
ILIM4VMLow voltage pin max voltage violatedA
VM5OUT1OUTx HiZB
OUT16PGNDLow voltage pin max voltage violatedA
PGND7OUT2Low voltage pin max voltage violatedA
OUT28GNDOUTx HiZB
Table 4-5 Pin FMA for Device Pins Short-Circuited to Supply
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
GND1Device will not power upB
IN22Low voltage pin max voltage violatedA
IN13Low voltage pin max voltage violatedA
ILIM4Low voltage pin max voltage violatedA
VM5Intended operationD
OUT16OUTx HiZB
PGND7Low voltage pin max voltage violatedA
OUT28OUTx HiZB