SFFS024 May 2022 TPS62872-Q1 , TPS62873-Q1
This section provides a Failure Mode Analysis (FMA) for the pins of the TPS62872-Q1 and TPS62873-Q1. 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 TPS62872-Q1 and TPS62873-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS62872-Q1 and TPS62873-Q1 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 |