SFFS148A november 2022 – june 2023 TPSI2140-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the TPSI2140-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:
- Pin short-circuited to Ground (see Table 4-2)
- Pin open-circuited (see Table 4-3)
- Pin short-circuited to Adjacent Pin (see Table 4-4)
Table 4-2 through Table 4-4 also indicate how these pin conditions can affect the device as per the failure effects classification in Table 4-1. Note that when pin short to ground case is discussed, only primary side ground shorts are considered.
| 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 |
Below is the TPSI2140-Q1 pin diagram package. For a detailed description of the device pins, see the Pin Configuration and Functions section in the TPSI2140-Q1 data sheet.
Figure 4-1 TPSI2140-Q1 Pin Diagram | Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| VDD | 1 | Device in OFF state (UVLO), secondary side switch in OFF state | B |
| GND | 2 | No effect | D |
| EN | 3 | Device in OFF State, secondary side switch in OFF state | B |
| NC/GND | 4 | No effect | D |
| NC/GND | 5 | No effect | D |
| NC/GND | 6 | No effect | D |
| NC/GND | 7 | No effect | D |
| GND | 8 | No effect | D |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| VDD | 1 | Device in OFF state (UVLO), secondary side switch in OFF state | B |
| GND | 2 | No effect | D |
| EN | 3 | Device in OFF State, secondary side switch in OFF state | B |
| NC/GND | 4 | No effect | D |
| NC/GND | 5 | No effect | D |
| NC/GND | 6 | No effect | D |
| NC/GND | 7 | No effect | D |
| GND | 8 | No effect | D |
| S2 | 9 | No effect | D |
| SM | 10 | No effect | D |
| S1 | 11 | No effect | D |
| Pin Name | Pin No. | Shorted to Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
| VDD | 1 | 2 | Device in OFF state (UVLO), secondary side switch in OFF state | B |
| GND | 2 | 3 | Device in OFF State, secondary side switch in OFF state | B |
| EN | 3 | 4 | No effect if pin 4 is NC, if pin 4 is GND the device will be in OFF state, secondary side switch in OFF state | D or B |
| NC/GND | 4 | 5 | No effect | D |
| NC/GND | 5 | 6 | No effect | D |
| NC/GND | 6 | 7 | No effect | D |
| NC/GND | 7 | 8 | No effect | D |
| S2 | 9 | 10 | Secondary side switch standoff voltage is halved. | C |
| SM | 10 | 11 | Secondary side switch standoff voltage is halved. | C |