SFFS792 January 2024 TPS62870 , TPS62871 , TPS62872 , TPS62873
This section provides a Failure Mode Analysis (FMA) for the pins of the TPS6287x. 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.
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 TPS6287x pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS6287x data sheet.
Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
COMP | 1 | The device does not power up and there is no output voltage. | B |
GOSNS | 2 | Normal operation, but output voltage accuracy gets worse | C |
VOSNS | 3 | Maximum duty cycle operation and no regulated output voltage. Output voltage follows the input voltage. | B |
EN | 4 | The device is disabled. Normal operation | C |
VIN | 5 | The device does not power up and there is no output voltage. | B |
GND | 6 | Normal operation | D |
SW | 7 | Potential device damage | A |
GND | 8 | Normal operation | D |
VIN | 9 | The device does not power up and there is no output voltage. | B |
PG | 10 | Normal operation and loss of PG indication | B |
MODE/SYNC | 11 | Normal operation. Power save mode is enabled. | C |
SDA | 12 | Normal operation and no I2C communication | B |
SCL | 13 | Normal operation and no I2C communication | B |
SYNC_OUT | 14 | Potential device damage | A |
VSEL | 15 | Normal operation. Defines start-up voltage | C |
FSEL | 16 | Normal operation. Defines switching frequency | C |
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
COMP | 1 | No loop compensation and can cause the output voltage to oscillate. Oscillation frequency cannot be predicted. | B |
GOSNS | 2 | No output voltage regulation and can cause the output voltage to oscillate. Oscillation frequency cannot be predicted. | B |
VOSNS | 3 | No output voltage regulation and can cause the output voltage to oscillate. Oscillation frequency cannot be predicted. | B |
EN | 4 | Undetermined device operation. The device can power up and operate normal. Stays turned off | B |
VIN | 5 | Normal operation. Pin 9 is still connected. | C |
GND | 6 | Normal operation. Pin 8 and the exposed thermal pad are still connected. | C |
SW | 7 | No output voltage | B |
GND | 8 | Normal operation. Pin 6 and the exposed thermal pad are still connected. | C |
VIN | 9 | Normal operation. Pin 5 is still connected. | C |
PG | 10 | Normal operation and loss of PG indication | B |
MODE/SYNC | 11 | Normal operation. Operation mode is undefined. | B |
SDA | 12 | Normal operation and no I2C communication | B |
SCL | 13 | Normal operation and no I2C communication | B |
SYNC_OUT | 14 | Normal operation | D |
VSEL | 15 | Normal operation. Start-up voltage is undefined. | B |
FSEL | 16 | Normal operation. Switching frequency is undefined. | B |
Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|---|
COMP | 1 | 2 | The device does not power up and there is no output voltage. | B |
GOSNS | 2 | 3 | Maximum duty cycle operation and no regulated output voltage. Output voltage follows the input voltage. | B |
VOSNS | 3 | 4 | The device does not power up or there is potential device damage. | A |
EN | 4 | 5 | Potential device damage | A |
VIN | 5 | 6 | The device does not power up and there is no output voltage. | B |
GND | 6 | 7 | Potential device damage | A |
SW | 7 | 8 | Potential device damage | A |
GND | 8 | 9 | The device does not power up and there is no output voltage. | B |
VIN | 9 | 10 | Potential device damage | A |
PG | 10 | 11 | Potential device damage if MODE/SYNC is tied high. Loss of PG indication | A |
MODE/SYNC | 11 | 12 | Potential device damage if MODE/SYNC is tied high. No I2C communication | A |
SDA | 12 | 13 | Normal operation and no I2C communication | B |
SCL | 13 | 14 | Potential device damage | A |
SYNC_OUT | 14 | 15 | Potential device damage if VSEL is tied high or low | A |
VSEL | 15 | 16 | Normal operation. Defines start-up voltage and switching frequency | B |
FSEL | 16 | 1 | No output voltage regulation and can cause output voltage oscillating. Oscillation frequency cannot be predicted. | B |
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
COMP | 1 | Potential device damage | A |
GOSNS | 2 | Potential device damage | A |
VOSNS | 3 | The device does not start up. Output voltage stays low or potential device damage. | A |
EN | 4 | Potential device damage | A |
VIN | 5 | Normal operation | D |
GND | 6 | The device does not power up and there is no output voltage. | B |
SW | 7 | Potential device damage | A |
GND | 8 | The device does not power up and there is no output voltage. | B |
VIN | 9 | Normal operation | D |
PG | 10 | Potential device damage | A |
MODE/SYNC | 11 | Normal operation and forced PWM operation | C |
SDA | 12 | Potential device damage | A |
SCL | 13 | Potential device damage | A |
SYNC_OUT | 14 | Potential device damage | A |
VSEL | 15 | Normal operation. Defines start-up voltage | C |
FSEL | 16 | Normal operation. Defines switching frequency | C |