SFFS958 July 2024 TPS62914-Q1 , TPS62916-Q1 , TPS62918-Q1
This section provides a failure mode analysis (FMA) for the pins of the TPS6291x-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:
Table 3-2 through Table 3-5 also indicate how these pin conditions can affect the device as per the failure effects classification in Table 3-1.
| 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 3-1 shows the TPS6291x-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS6291x-Q1 data sheet.
Following is the assumption of use and the device configuration assumed for the pin FMA in this section:
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| PSNS | 1 | Intended pin connection. | D |
| NR/SS | 2 | The device does not power on. | B |
| FB | 3 | Loss of output voltage regulation. Output voltage goes to Vin. Device damage is possible.(1) Absolute maximum voltage can be exceeded. | A |
| VO | 4 | Loss of output voltage. | B |
| PG | 5 | Loss of PG functionality. | C |
| S-CONF | 6 | The device runs at 1MHz fSW, spread spectrum off, output discharge off, sync disabled.(2) | C (2) |
| EN/SYNC | 7 | The device does not power on for both EN and SYNC functions. | B |
| VIN | 8, 12 | The device does not power on. | B |
| PGND | 9, 11 | Intended pin connection. | D |
| SW | 10, 13 | Device damage is possible. | A |
| BOOT | 14 | Device damage is possible. | A |
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| PSNS | 1 | Device damage is possible. | A |
| NR/SS | 2 | Allowable pin condition. Soft-start time is minimized. Minimum noise filtering. | D |
| FB | 3 | Loss of output voltage regulation. Output voltage goes to Vin. Device damage is possible.(1) Absolute maximum voltage can be exceeded. | A |
| VO | 4 | Open loop operation. Undetermined output voltage behavior. | B |
| PG | 5 | Loss of PG functionality. | C |
| S-CONF | 6 | The device runs at 2.2Mhz fSW, spread spectrum random, output discharge on, sync disabled.(2) | C |
| EN/SYNC | 7 | The device does not power on for both EN and SYNC functions. | B |
| VIN | 8, 12 | The device does not power on. | B |
| PGND | 9, 11 | Device damage is possible. | A |
| SW | 10, 13 | Loss of output voltage regulation. | B |
| BOOT | 14 | Loss of output voltage regulation. | B |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|---|
| PSNS | 1 | NR/SS | The device does not power on. | B |
| NR/SS | 2 | FB | Loss of output voltage regulation. | B |
| FB | 3 | VO | Loss of output voltage regulation. | B |
| VO | 4 | PG | Loss of output voltage regulation. Device damage is possible.(1) Absolute maximum voltage can be exceeded if PG is connected to VIN through a resistor. | A |
| PG | 5 | S-CONF | The device operating mode is indeterminate. (2) | C (2) |
| S-CONF | 6 | EN/SYNC | The device operating mode is indeterminate. (2) | C (2) |
| EN/SYNC | 7 | VIN | The device cannot be disabled. If using SYNC functionality, loss of output voltage regulation occurs. | B |
| VIN | 8 | PGND | Device damage is possible. | A |
| PGND | 9 | SW | Device damage is possible. | A |
| SW | 10 | PGND | Device damage is possible. | A |
| PGND | 11 | VIN | Device damage is possible. | A |
| VIN | 12 | SW | Device damage is possible. | A |
| SW | 13 | BOOT | Device damage is possible. | A |
| BOOT | 14 | PSNS | Device damage is possible. | A |
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| PSNS | 1 | Device damage is possible. | A |
| NR/SS | 2 | Device damage is possible.(1) Absolute maximum voltage can be exceeded. | A |
| FB | 3 | Loss of output voltage regulation. Output voltage goes to Vin. Device damage is possible.(1) Absolute maximum voltage can be exceeded. | A |
| VO | 4 | Device damage is possible.(1) Absolute maximum voltage can be exceeded. | A |
| PG | 5 | Device damage is possible. Absolute maximum current rating for the pin can be exceeded. | A |
| S-CONF | 6 | The device runs at 2.2MHz fSW, spread spectrum off, output discharge off, sync disabled.(2) | D (2) |
| EN/SYNC | 7 | The device cannot be disabled. If using SYNC functionality, loss of output voltage regulation occurs. | B |
| VIN | 8, 12 | Intended pin connection. | D |
| PGND | 9, 11 | Device damage is possible. | A |
| SW | 10, 13 | Device damage is possible. | A |
| BOOT | 14 | Device damage is possible. | A |