SFFS015 April   2021 TPS62816-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 TPS62816-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:

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 TPS62816-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS62816-Q1datasheet.

GUID-A7D00462-CB3A-424A-8D86-355B093F3B20-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:

  • Assumption the device is running in the typical application, please refer to the 'Simplified Schematics' on the

    1st page in the TPS62816-Q1datasheet.

Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
MODE/SYNC1Normal operationD
VIN2Device does not power up, no output voltageB
SW3Potential device damageA
GND4Normal operationD
FB5100% duty cycle mode, output voltage follows the input voltageB
SS/TR6Device does not start properly, no output voltageB
COMP/FSET7Normal operationD
EN8Device is disabled, no output voltageB
PG9Normal operation, no power good indicationB
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
MODE/SYNC1Device either operates in forced PWM or power save mode enabled. Output voltage is regulated to its nominal value.B
VIN2Device does not power up, no output voltageB
SW3 No output voltageB
GND4Device does not power up, no output voltageB
FB5100% or 0% duty cycle operation, no regulated output voltage. Output voltage either follows the input voltage or no output voltageB
SS/TR6Normal operationD
COMP/FSET7Normal operationD
EN8Device is either enabled or disabled. If enabled, output voltage is regulated to its nominal value. If disabled no output voltageB
PG9Normal operationB
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
MODE/SYNC12Normal operationD
VIN23Potential device damageA
SW34Potential device damageA
GND45100% duty cycle mode, output voltage follows the input voltageB
FB560% duty cycle mode, no output voltage B
SS/TR67Normal operationD
COMP/FSET74Normal operationD
EN 8 2 Normal operation D
EN89 Device does not power up, no output voltageB
PG91Device operates in forced PWM once PG is high impedance. Output voltage is regulated to its nominal value.B
Table 4-5 Pin FMA for Device Pins Short-Circuited to VIN
Pin NamePin No.Description of Potential Failure Effect(s)Failure Effect Class
MODE/SYNC1Normal operationD
VIN2Normal operationD
SW3Potential device damageA
GND4Device does not power up, no output voltageB
FB5Potential device damageA
SS/TR6Normal operationD
COMP/FSET7Normal operationD
EN8Normal operationD
PG9Potential device damage

A