SFFS571 February   2023 TPS7B83-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 TPS7B83-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
Class Failure Effects
A Potential device damage that affects functionality.
B No device damage, but loss of functionality.
C No device damage, but performance degradation.
D No device damage, no impact to functionality or performance.

Figure 4-1 shows the TPS7B83-Q1 pin diagram. For a detailed description of the device pins, see the Pin Configuration and Functions section in the TPS7B83-Q1 data sheet.

GUID-479EB2B2-4C69-400C-B263-D1577A1B13DD-low.gif Figure 4-1 Pin Diagram
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. Description of Potential Failure Effects Failure Effect Class
IN 1 No output voltage. System performance depends on upstream current limiting. B
GND 2 No effect. Normal operation. D
OUT 3 Current limit is triggered, and the device can repeatedly enter and exit thermal shutdown depending on power dissipation. B
GND 4 No effect. Normal operation. D
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. Description of Potential Failure Effects Failure Effect Class
IN 1 Power is not supplied to the device, resulting in no output voltage. B
GND 2 A floating GND pin can result in incorrect voltage regulation or no output voltage. B
OUT 3 The output is disconnected from the load. B
GND 4 A floating GND pin can result in incorrect voltage regulation or no output voltage. B
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin Name Pin No. Shorted to Description of Potential Failure Effects Failure Effect Class
IN 1 GND No output voltage. System performance depends on upstream current limiting. B
GND 2 OUT Current limit is triggered, and the device can repeatedly enter and exit thermal shutdown depending on power dissipation. B
OUT 3 GND Current limit is triggered, and the device can repeatedly enter and exit thermal shutdown depending on power dissipation. B
Table 4-5 Pin FMA for Device Pins Short-Circuited to Supply
Pin Name Pin No. Description of Potential Failure Effects Failure Effect Class
IN 1 No effect. Normal operation. D
GND 2 No output voltage. System performance depends on upstream current limiting. B
OUT 3 The output is not regulated. VOUT = VIN. The OUT pin can be damaged if the absolute maximum rating (7 V) is violated. B/A
GND 4 No output voltage. System performance depends on upstream current limiting. B