SFFS263 October 2021 INA301-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the INA301-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 INA301-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the INA301-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:
- TA = -40°C to +125°C
- VS = 5 V
- VIN+ = 12 V
- REF = VS/2.
Table 4-2 Pin FMA for Device Pins Short-Circuited to
Ground
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| VS | 1 | Power supply shorted to ground. | B |
| OUT | 2 | Output shorts to ground. When left in this configuration for a long time, under high supplies self heating could cause dice junction temperature to exceed 150 degrees Celsius. | B |
| LIMIT | 3 | ALERT output is stuck low. | B |
| GND | 4 | Normal Operation. | D |
| RESET | 5 | If intended connection is not GND, functionality will be affected. | D if RESET=GND by design; C otherwise |
| ALERT | 6 | ALERT output is stuck low. | B |
| IN- | 7 | In high-side configuration, a short from the bus supply to GND will occur. High current will flow from bus supply to ground. In low-side configuration, normal operation. | B for high-side or D for low-side |
| IN+ | 8 | In high-side configuration, a short from the bus supply to GND will occur. High current will flow from bus supply to ground. In low side configuration, input pins are shorted. | B |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| VS | 1 | No power supply to device. Device may be biased through inputs. Output will be close to GND. | B |
| OUT | 2 | Output can be left open, there is no effect on the IC. | D |
| LIMIT | 3 | Comparator threshold is not defined. | B |
| GND | 4 | Output will be incorrect as it is no longer referenced to GND. | B |
| RESET | 5 | Comparator mode is not defined. | B |
| ALERT | 6 | Pin can be left open if not needed. | D |
| IN- | 7 | Differential input voltage is not well defined. | B |
| IN+ | 8 | Differential input voltage is not well defined. | B |
Table 4-4 Pin FMA for Device Pins Short-Circuited to
Adjacent Pin
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
| VS | 1 | OUT | Output shorts to supply. When left in this configuration for a long time, under high supplies self heating could cause dice junction temperature to exceed 150 degrees Celsius. | B |
| OUT | 2 | LIMIT | Comparator output will be unpredictable. | B |
| LIMIT | 3 | GND | ALERT output is stuck low. | B |
| GND | 4 | RESET | If intended connection is not GND, functionality will be affected. | D if RESET=GND by design; C otherwise |
| RESET | 5 | ALERT | ALERT Comparator output will be unpredictable. | B |
| ALERT | 6 | IN- | In low-side configuration, ALERT output is stuck low; In high-side configuration, device damage is possible. | C for low-side; A for high-side |
| IN- | 7 | IN+ | Input differential voltage=0V. | C |
| IN+ | 8 | VS | In high-side configuration, a short from the bus supply to VS will occur. High current will flow from bus supply to VS or vice versa. Device could be damaged. | A |
Table 4-5 Pin FMA for Device Pins Short-Circuited to
Supply
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| VS | 1 | Normal operation. | D |
| OUT | 2 | Output shorts to supply. When left in this configuration for a long time, under high supplies self heating could cause dice junction temperature to exceed 150 degrees Celsius. | B |
| LIMIT | 3 | ALERT is stuck high or unpredictable. | B |
| GND | 4 | Power supply shorted to GND. | B |
| RESET | 5 | Comparator1 in Latch mode. | D if RESET=VS by design; C otherwise |
| ALERT | 6 | ALERTis stuck high. Power supply could be shorted to GND though this pin. | A |
| IN- | 7 | In high-side configuration, a short from the bus supply to VS will occur. High current will flow from bus supply to VS or vice versa. Device could be damaged. | A for High side or B for low side |
| IN+ | 8 | In high-side configuration, a short from the bus supply to VS will occur. High current will flow from bus supply to VS or vice versa. Device could be damaged. | A for High side or B for low side |