SFFS190 March   2022 UCC27517A-Q1 , UCC27518A-Q1 , UCC27519A-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 UCC27517A-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 4-4)
  • Pin short-circuited to an adjacent pin (see Table 4-6)
  • Pin short-circuited to supply (see Table 4-8)

Table 4-2 through Table 4-8 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 UCC27517A-Q1 UCC27518A-Q1 UCC27519A-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the data sheet.

GUID-9CD616A2-E6B1-44A5-B565-5C9B0E08582F-low.gif Figure 4-1 UCC27517A-Q1 Pin Diagram
GUID-10B95B61-A665-4095-B2D0-0310F4404ED0-low.gif Figure 4-2 UCC27518A-Q1 Pin Diagram
GUID-9AEFC635-AAED-4A6E-85FC-C7A0DACEB18E-low.gif Figure 4-3 UCC27519A-Q1

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

  • Pin #4 and 5 short case not considered.
  • Short between corner pins are not considered.
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. UCC27517A-Q1 Description of Potential Failure Effect(s) Failure Effect Class
VDD 1 VDD and GND short circuit. No power is applied to the device. D
GND 2 Short to same potential. No impact. D
IN+ 3 OUT stuck low. B
IN- 4 OUT responds to IN+. IN- stuck low. B
OUT 5 Posiible OUT pin and driver damge. A
Table 4-3 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. UCC27518A-Q1 UCC27519A-Q1Description of Potential Failure Effect(s) Failure Effect Class
EN 1 OUT is disabled B
GND 2 Short to same potential. No impact. D
IN- 3 OUT stuck high. B
IN+ 3 OUT stuck low B
OUT 4 Posiible OUT pin and driver damge. A
VDD 5 VDD and GND short circuit. No power is applied to the device. D
Table 4-4 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
VDD 1 No power is applied to the device. D
GND 2 OUT is pulled up to VDD level. B
IN+ 3 OUT stuck low. B
IN- 4 OUT stuck low. B
OUT 5 OUT operates normally. Connection to the gate of Power FET is lost. B
Table 4-5 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. UCC27518A-Q1 UCC27519A-Q1Description of Potential Failure Effect(s) Failure Effect Class
EN 1 OUT is enabled B
GND 2 OUT stuck high. B
IN- 3 OUT stuck low. B
IN+ 3 OUT stuck low. B
OUT 4 OUT is floating B
VDD 5 No power is applied to the device. B
Table 4-6 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin Name Pin No. Shorted to Description of Potential Failure Effect(s) Failure Effect Class
VDD 1 GND VDD and GND short circuit. No power is applied to the device. D
GND 2 IN+ OUT stuck low. B
Table 4-7 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin Name Pin No. Shorted to UCC27518A-Q1 UCC27519A-Q1 Description of Potential Failure Effect(s) Failure Effect Class
EN 1 GND OUT is disabled B
GND 2 IN- OUT stuck high. B
GND 2 IN+ OUT stuck low. B
Table 4-8 Pin FMA for Device Pins Short-Circuited to supply
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
VDD 1 Short to same potential. No impact. D
GND 2 VDD and GND short circuit. No power is applied to the device. D
IN+ 3 OUT stuck high if IN- is low. B
IN- 4 OUT stuck low. B
OUT 5 Possible OUT pin and driver damge. A
Table 4-9 Pin FMA for Device Pins Short-Circuited to supply
Pin Name Pin No. UCC27518A-Q1 UCC27519A-Q1Description of Potential Failure Effect(s) Failure Effect Class
EN 1 OUT is enabled. EN is stuck high. B
GND 2 VDD and GND short circuit. No power is applied to the device. D
IN- 3 OUT stuck low. B
IN+ 3 OUT stuck high. B
OUT 4 Possible OUT pin and driver damge. A
VDD 5 Short to same potential. No impact. D