SLVAEY6 November   2020 TPS3813-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 TPS3813-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 TPS3813-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS3813-Q1 data sheet.

GUID-CF47633E-ECB1-4FB0-90A3-74CC2C7EE58D-low.svg Figure 4-1 Top View6-Pin SOT-23DBV Package

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

Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
WDI 1 No damage but will cause /RESET to C
GND 2 Normal operation D
WDT 3 Normal operation mode D
VDD 4 No damage to device, but undefined condition. /RESET tends to be low C
WDR 5 Normal operation mode D
/RESET 6 Normal operation; causes /RESET to be low C
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
WDI 1 No damage to device but will cause /RESET to time out C
GND 2 No damage to device, but undefined operating condition C
WDT 3 No damage to device, but it is an undefined operating condition C
VDD 4 No power to device C
WDR 5 No damage to device, but it is an undefined operating condition C
/RESET 6 Normal operation, causes reset to be low C
Table 4-4 Pin FMA for Device Pins Short-Circuited to Relevant Pin
Pin Name Pin No. Shorted to Description of Potential Failure Effect(s) Failure Effect Class
WDI 1 WDR No damage to device but will cause /RESET to oscillate C
GND 2 /RESET Normal operation; causes /RESET to be low C
WDT 3 GND Normal operation mode D
VDD 4 WDI No damage to device but will cause /RESET to timeout C
WDR 5 WDT Normal operation D
/RESET 6 VDD No damage to device, but it is an undefined operating conditon; /RESET needs pullup resistor C
Table 4-5 Pin FMA for Device Pins Short-Circuited to VDD
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
WDI 1 No damage to device, but will cause /RESET to time out C
GND 2 Normal operation. Internally pulled up to VDD, external short may cause excess current consumption C
WDT 3 Normal operation mode D
VDD 4 Normal operation D
WDR 5 Normal operation mode D
/RESET 6 No damage to device but is an undefined operating condition. Needs pullup C