SFFS626 February 2024 TPS1HTC30-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the TPS1HTC30-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 VS (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 TPS1HTC30-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS1HTC30-Q1 data sheet.
Figure 4-1 Pin
Diagram Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- Follows data sheet recommendation for operating conditions, external components selection, and PCB layout
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 |
|---|---|---|---|
| GND | 1 | Resistor, diode network is bypassed if present | B |
| EN | 2 | Shutdown of corresponding channel | B |
| DIAG_EN | 3 | Diagnostics are disabled | B |
| FAULT | 4 | Status being reported can be erroneous | B |
| LATCH | 5 | Device defaults to auto-retry mode when encountering thermal fault | B |
| SNS | 6 | Sense current not valid from SNS pin | B |
| ILIM | 7 | Device defaults to internal open current limit | C |
| NC | 11 | No effect | D |
| VOUT | 8,9,10 | Current limit of device engages | B |
| VS | 12,13,14 | Device has no input supply and therefore does not function | B |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| GND | 1 | Loss of ground detection engages and device shuts off | B |
| EN | 2 | Corresponding channel is shutdown and EN is pulled down internally | B |
| DIAG_EN | 3 | Internally pulled down. Diagnostics are disabled. | B |
| FAULT | 4 | Fault signal not reported | B |
| LATCH | 13 | Internally pulled down. Device defaults to auto-retry mode when encountering thermal fault | B |
| SNS | 10 | Version B only. Correct sense current cannot be read. | B |
| ILIM | 11 | Device defaults to internal current limit | C |
| NC | 11 | No effect | D |
| VOUT | 8,9,10 | No effect. If configured, open load detection triggers | B |
| VS | 12,13,14 | Device has no input supply and therefore does not function | 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 |
|---|---|---|---|---|
| GND | 1 | EN | Channel is disabled | B |
| EN | 2 | DIAG_EN | EN signal affects DIAG_EN signal and vice versa | B |
| DIAG_EN | 3 | FAULT | Fault reporting is erroneous. Diagnostics are enabled if FAULT is pulled high. | B |
| FAULT | 4 | LATCH | Fault reporting is erroneous. Device is in auto-retry mode if FAULT is pulled high. | B |
| LATCH | 5 | SNS | Current sensing output is erroneous. Device is in auto-retry or latched off depending on the output of the SNS pin. | B |
| SNS | 6 | ILIM | Current limit and current sensing output is incorrect | B |
| VOUT | 10 | NC | No effect | D |
| NC | 11 | VS | No effect | D |
Table 4-5 Pin FMA for Device Pins Short-Circuited to
supply (VS)
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| GND | 1 | Supply power is bypassed and device does not turn on | B |
| EN | 2 | Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell | A |
| DIAG_EN | 3 | Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell | A |
| FAULT | 4 | Version B only. Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell. | A |
| LATCH | 5 | Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell | A |
| SNS | 6 | Version B only. Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell | A |
| ILIM | 7 | Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell | A |
| NC | 11 | No effect | D |
| VOUT | 8,9,10 | Output is pulled to supply voltage. Short-to-battery detection is triggered if configured. | B |