SFFS963 February 2025 TMP411-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the TMP411-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.
Table 4-1 TI Classification of Failure Effects
| 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 TMP411-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TMP411-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:
- Device is the only target on the I2C bus
- External pull-up resistor on SCL and SDA pins
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| V+ | 1 | The device is not powered. The device is not functional. Observe that the absolute maximum ratings for all pins of the device are met, otherwise, device damage is plausible. | A |
| D+ | 2 | The positive remote connection is stuck low. The remote temperature measurement is out of specification. | B |
| D- | 3 | No effect. Normal operation. | D |
| THERM | 4 | THERM is stuck low. Not functional. A false thermal limit triggers. | B |
| GND | 5 | No effect. Normal operation. | D |
| ALERT/THERM2 | 6 | ALERT/THERM2 is stuck low. Not functional. A false thermal limit triggers. | B |
| SDA | 7 | SDA is stuck low. I2C communication with the device is not possible. | B |
| SCL | 8 | SCL is stuck low. I2C communication with the device is not possible. | B |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| V+ | 1 | The functionality of the device is undetermined. The device is not powered if all external analog and digital pins are held low. If voltages are present on any of the analog or digital pins above the power-on reset threshold for the device, the device can potentially power up through internal ESD diodes to V+. | B |
| D+ | 2 | The positive remote connection is undetermined. The remote temperature measurement is out of specification. | B |
| D- | 3 | The reference of remote connection is undetermined. The remote temperature measurement is out of specification. | B |
| THERM | 4 | The state of THERM is undetermined. A false thermal limit can trigger. | B |
| GND | 5 | The functionality of the device is undetermined. The device can be not powered or connected to ground internally through an alternate pin ESD diode and powered up. | B |
| ALERT/THERM2 | 6 | The state of ALERT/THERM2 is undetermined. A false thermal limit can trigger. | B |
| SDA | 7 | The state of SDA is undetermined. I2C communication with the device is not possible. | B |
| SCL | 8 | The state of SCL is undetermined. I2C communication with the device is not possible. | B |
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|---|
| V+ | 1 | D+ | The positive remote connection is stuck high. The remote temperature measurement is out of specification. | B |
| D+ | 2 | D- | The positive remote connection and the reference of remote connection is shorted. The remote temperature measurement is out of specification. | B |
| D- | 3 | THERM | The reference of remote connection is stuck high or low. The remote temperature measurement is out of specification. | B |
| GND | 4 | ALERT/THERM2 | ALERT is stuck low. Not functional. A false thermal limit triggers. | B |
| ALERT/THERM2 | 5 | SDA | The SDA communication line is stuck high or low. I2C communication with the device is not possible. | B |
| SDA | 6 | SCL | The communication lines are shorted. I2C communication with the device is not possible. | B |
Table 4-5 Pin FMA for Device Pins Short-Circuited to
Supply
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| V+ | 1 | No effect. Normal operation. | D |
| D+ | 2 | The positive remote connection is stuck high. The remote temperature measurement is out of specification. | B |
| D- | 3 | The reference of remote connection is stuck high. The remote temperature measurement is out of specification. | B |
| THERM | 4 | THERM is stuck high. Not functional. The thermal limit does not trigger. | B |
| GND | 5 | The device functionality is undetermined. Observe that the absolute maximum ratings for all pins of the device are met, otherwise, device damage is plausible. | A |
| ALERT/THERM2 | 6 | ALERT/THERM2 is stuck high. Not functional. The thermal limit does not trigger. | B |
| SDA | 7 | SDA is stuck high. I2C communication with the device is not possible. | B |
| SCL | 8 | SCL is stuck high. I2C communication with the device is not possible. | B |