SFFS338 March 2022 TPS62441 , TPS62442
This section provides a Failure Mode Analysis (FMA) for the pins of the TPS6244x. 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 TPS6244x pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS6244x data sheet.
Figure 4-1 Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
Assumption the device is running in the typical application, please refer to the 'Simplified Schematics' on the first page in the TPS6244x data sheet.
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
FB2 | 1 | Converter 2 output voltage regulated to VIN (100% mode) | B |
GND | 2 | No effect, normal operation | D |
FB1 | 3 | Converter 1 output voltage regulated to VIN (100% mode) | B |
PG1 | 4 | No operation, no power-good indication | B |
MODE/SYNC | 5 | Intended functionality | D |
SW1 | 6 | Potential device damage | A |
VIN1 | 7 | Converter 1 does not power up. No output voltage on converter 1 | B |
EN1 | 8 | Converter 1 is disabled. No output voltage on converter 1 | B |
GND | 9 | No effect, normal operation | D |
EN2 | 10 | Converter 2 is disabled. No output voltage on converter 2 | B |
VIN2 | 11 | Converter 2 does not power up. No output voltage on converter 2 | B |
SW2 | 12 | Potential device damage | A |
PG2 | 13 | No operation, no power-good indication | B |
COMP/FSET | 14 | Intended functionality, device operates in fixed frequency. | D |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
FB2 | 1 | Undetermined output voltage behavior of converter 2; open loop operation | B |
GND | 2 | Device does not power up. No output voltage | B |
FB1 | 3 | Undetermined output voltage behavior of converter 1; open loop operation | B |
PG1 | 4 | Intended functionality | B |
MODE/SYNC | 5 | Undetermined device operation | B |
SW1 | 6 | Output voltage 1 not functional, open loop operation | B |
VIN1 | 7 | Converter 1 does not power up. | B |
EN1 | 8 | Undetermined device operation; converter 1 might power up or not. | B |
GND | 9 | Device does not power up. No output voltage | B |
EN2 | 10 | Undetermined device operation; converter 2 might power up or not. | B |
VIN2 | 11 | Converter 2 does not power up. | B |
SW2 | 12 | Converter 2 is not functional. Open loop operation | B |
PG2 | 13 | Intended functionality | B |
COMP/FSET | 14 | Normal operation | D |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
FB1 | 3 | PG1 | Converter 2 does not regulate. | B |
PG1 | 4 | MODE/SYNC | No device damage, but performance degradation | B |
MODE/SYNC | 5 | SW1 | Potential internal device damage | A |
SW2 | 12 | PG2 | Potential internal device damage | A |
PG2 | 13 | COMP/FSET | Potential internal device damage | A |
COMP/FSET | 14 | FB2 | Converter 2 does not regulate. | B |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
FB2 | 1 | Potential device damage | A |
GND | 2 | Device does not power up. No output voltage | B |
FB1 | 3 | Potential device damage | A |
PG1 | 4 | Potential device damage | A |
MODE/SYNC | 5 | Intended functionality; FPWM mode | D |
SW1 | 6 | Potential device damage | A |
VIN1 | 7 | Normal operation | D |
EN1 | 8 | Intended functionality; converter 1 enable | D |
GND | 9 | Device does not power up. No output voltage | B |
EN2 | 10 | Intended functionality; converter 2 enable | D |
VIN2 | 11 | Normal operation | D |
SW2 | 12 | Potential device damage | A |
PG2 | 13 | Potential device damage | A |
COMP/FSET | 14 | Intended functionality; device operates in fixed frequency. | D |