SFFS797 February   2024 TXU0202-Q1

 

  1.   1
  2.   Trademarks
  3. 1Overview
  4. 2Functional Safety Failure In Time (FIT) Rates
  5. 3Failure Mode Distribution (FMD)
  6. 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 TXU0202-Q1 (VSSOPand SON package). The failure modes covered in this document include the typical pin-by-pin failure scenarios:

Table 4-2 through Table 4-6 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

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

Figure 4-1 shows the TXU0202-Q1 pin diagram for the VSSOP package. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TXU0202-Q1 data sheet.

GUID-C418B045-0F76-48AD-A1DF-D4EEC3EEE0C7-low.svg Figure 4-1 Pin Diagram (VSSOP) Package

Figure 4-2 shows the TXU0202-Q1 pin diagram for the SON package. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TXU0202-Q1 data sheet.

GUID-D40DDBA0-4348-4BBA-B472-81D5B8EEDA93-low.svg Figure 4-2 Pin Diagram (SON Package)
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
B2 1 Bx will be LOW, if corresponding Ax is HIGH, there will be potential damage to the device if the current is not limited. If corresponding Ax is LOW, then nothing will occur, no damage. B
GND 2 Normal operation. D
VCCA 3 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
A2Y 4 Ax will be lLOW, if corresponding Bx is HIGH, there will be potential damage to the device if the current is not limited. If corresponding Bx is LOW, then nothing will occur, no damage. B
A1 5 B
OE 6 All I/Os will be fixed into high impedance (tri-state). B
VCCB 7 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
B1Y 8 Bx will be LOW, if corresponding Ax is HIGH, there will be potential damage to the device if the current is not limited. If corresponding Ax is LOW, then nothing will occur, no damage. B
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
B2 1 Bx pin will be grounded internally. D
GND 2 Device will not be powered. B
VCCA 3 Device will not be powered. B
A2Y 4 Normal operation. D
A1 5 Ax pin will be grounded internally. B
OE 6 I/Os may be high impedance or active, unknown input state. A
VCCB 7 Device will not be powered. B
B1Y 8 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 Effect(s) Failure Effect Class
B2 1 GND Bx will be LOW, if corresponding Ax is HIGH, there will be potential damage to the device if the current is not limited. If corresponding Ax is LOW, then nothing will occur, no damage. B
GND 2 VCCA Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
VCCA 3 A2 Ax will be HIGH, if corresponding Bx is LOW, there will be potential damage to the device if the current is not limited. If corresponding Bx is HIGH, then nothing will occur, no damage. B
A2Y 4 A1 One output on VCCA supply is shorted to one input of VCCA supply. Based on the external bus driving this connection, potential high current can be expected if the VILA < Input Voltage A1 < VIHA or if A2Y output gets an undeterministic voltage forced on it in presence of a valid input. A
A1 5 OE If A1 is HIGH, device will be enabled. If A1 is LOW, device will be disabled B
OE 6 VCCB All I/Os will be active, device cannot be disabled. B
VCCB 7 B1Y Bx will be HIGH, if corresponding Ax is LOW, there will be potential damage to the device if the current is not limited. If corresponding Ax is HIGH, then nothing will occur, no damage. B
B1Y 8 B2 One output on VCCB supply is shorted to one input of VCCB supply. Based on the external bus driving this connection, potential high current can be expected if the VILB < Input Voltage B2 < VIHB or if B1Y output gets an undeterministic voltage forced on it in presence of a valid input. A
Table 4-5 Pin FMA for Device Pins Short-Circuited to supply VCCA
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
B2 1 Bx will be HIGH, if corresponding Ax is LOW, there will be potential damage to the device if the current is not limited. If corresponding Ax is HIGH, then nothing will occur, no damage. B
GND 2 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
VCCA 3 Normal operation. D
A2Y 4 Ax will be HIGH, if corresponding Bx is LOW, there will be potential damage to the device if the current is not limited. If corresponding Bx is HIGH, then nothing will occur, no damage. B
A1 5 B
OE 6 All I/Os will be active, device cannot be disabled. B
VCCB 7 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
B1Y 8 Bx will be HIGH, if corresponding Ax is LOW, there will be potential damage to the device if the current is not limited. If corresponding Ax is HIGH, then nothing will occur, no damage. B
Table 4-6 Pin FMA for Device Pins Short-Circuited to supply VCCB
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
B2 1 Bx will be HIGH, if corresponding Ax is LOW, there will be potential damage to the device if the current is not limited. If corresponding Ax is HIGH, then nothing will occur, no damage. B
GND 2 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
VCCA 3 Device will not be powered or damaged, because short is external to device. System level damage may occur in this scenario. B
A2Y 4 Ax will be HIGH, if corresponding Bx is LOW, there will be potential damage to the device if the current is not limited. If corresponding Bx is HIGH, then nothing will occur, no damage. B
A1 5 B
OE 6 All I/Os will be active, device cannot be disabled. B
VCCB 7 Normal operation. D
B1Y 8 Bx will be HIGH, if corresponding Ax is LOW, there will be potential damage to the device if the current is not limited. If corresponding Ax is HIGH, then nothing will occur, no damage. B