SFFS591 March   2023 TPS7B4255-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 DBV Package
    2. 2.2 DYB Package
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 DBV Package
    2. 4.2 DYB Package

DBV Package

Figure 4-1 shows the TPS7B4255-Q1 pin diagram for the DBV package. For a detailed description of the device pins, see the Pin Configuration and Functions section in the TPS7B4255-Q1 data sheet.

Figure 4-1 Pin Diagram (DBV) Package
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. Description of Potential Failure Effects Failure Effect Class
ADJ/EN 1 The device is disabled, resulting in no output voltage. B
GND 2 No effect. Normal operation. D
IN 3 Power is not supplied to the device. System performance depends on upstream current limiting. B
OUT 4 Regulation is not possible, the device operates at current limit. The device can cycle in and out of thermal shutdown. B
NC 5 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
ADJ/EN 1 The device state is unknown. If the device is on, the output voltage is indeterminate. B
GND 2 There is no current loop for the supply voltage. The device is not operational and does not regulate. B
IN 3 Power is not supplied to the device. B
OUT 4 The device output is disconnected from the load. B
NC 5 No effect. Normal operation. D
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
ADJ/EN 1 GND The device is disabled, resulting in no output voltage. B
GND 2 IN Power is not supplied to the device. System performance depends on upstream current limiting. B
OUT 4 NC No effect. Normal operation. D
Table 4-5 Pin FMA for Device Pins Short-Circuited to Supply
Pin Name Pin No. Description of Potential Failure Effects Failure Effect Class
ADJ/EN 1 The device operates as a switch in dropout mode. The output tracks the input minus the dropout voltage. B
GND 2 Power is not supplied to the device. System performance depends on upstream current limiting. B
IN 3 No effect. Normal operation. D
OUT 4 Regulation is not possible. VOUT = VIN. B
NC 5 No effect. Normal operation. D