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)

4 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