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)

4 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