SFFS633 August 2025 TPS22995H-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the TPS22995H-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 an adjacent pin (see Table 4-4)
- Pin short-circuited to supply (see Table 4-5)
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 TPS22995H-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS22995H-Q1 data sheet.
Figure 4-1 Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- The device pins are connected per the recommendation in the data sheet, including pullup and pulldown resistors, as needed.
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| VBIAS | 1 | No power supply to the device. The device does not pass through voltage to VOUT. | B |
| VIN | 2 | The power supply is shorted. | D |
| ON | 3 | The device is disabled. | D |
| GND | 4 | This is the GND pin. Normal operation. | D |
| VOUT | 5 | If the device is enabled, the device does not limit the power supply current and is damaged. | A |
| RT | 6 | Grounding this pin quickens the output rise time more than expected if an RT resistor is connected or the pin is intended to be left open. | C |
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| VBIAS | 1 | No power supply to the device. The device does not pass through voltage to VOUT. | B |
| VIN | 2 | No power supply to the device. The device does not pass through voltage to VOUT. | D |
| ON | 3 | The ON pin can float high or low, the output state is unknown. | D |
| GND | 4 | No GND connection to the device. Not functional. | D |
| VOUT | 5 | The output does not deliver the voltage to the load. | D |
| RT | 6 | Opening this pin slows down the output rise time more than expected if an RT resistor is attached or the pin is intended to be grounded. | C |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|---|
| VBIAS | 1 | VIN | A stronger supply powers the IN and BIAS pins. Device operation can be affected, no device damage. | D |
| VIN | 2 | ON | The device is enabled if the VIN power supply is above the ON threshold (VIH). | D |
| GND | 4 | VOUT | If the device is enabled, the device does not limit the power supply current and is damaged. | A |
| VOUT | 5 | RT | Shorting this pin quickens the output rise time more than expected if an RT resistor is attached. | C |
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| VBIAS | 1 | Normal operation is expected. | D |
| VIN | 2 | Normal operation is expected. | D |
| ON | 3 | The device is enabled if the power supply is above the ON threshold (VIH). | D |
| GND | 4 | The power supply is shorted. | D |
| VOUT | 5 | The power MOSFET is shorted. Disabling the device no longer blocks power to VOUT. | B |
| RT | 6 | The output rise time slows down. | C |