SFFS068 March 2021 TLIN2021A-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the TLIN2021A-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 TLIN2021A-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TLIN2021A-Q1 data sheet.
Figure 4-1 DRB Pin Diagram
Figure 4-2 D and DDF Pin
DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- All conditions within the recommended operating conditions
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 |
|---|---|---|---|
| RXD | 1 | RXD biased dominant, no communication from LIN bus to MCU possible | B |
| EN | 2 | Device may only operate in Standby Mode after power-on. If short occures in Normal mode, the part would be forced to enter sleep mode and could disable LIN communication | B |
| WAKE | 3 | WAKE pin biased to ground and no local wake up possible | B |
| TXD | 4 | TXD biased dominant, no communication from MCU to LIN bus possible | B |
| GND | 5 | None | D |
| LIN | 6 | LIN biased dominant, no LIN communication possible | B |
| VSUP | 7 | Device is unpowered and will not function | B |
| INH | 8 | INH biased to GND, will not be able to enable system power if used in this manner | B |
Note: DRB package includes a thermal pad
Table 4-3 Pin FMA for Device Pins
Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| RXD | 1 | No communication from LIN bus to MCU possible | B |
| EN | 2 | Biased low due to internal pull-down so device in standby mode | B |
| WAKE | 3 | No local wake up possible | B |
| TXD | 4 | No communication from MCU to LIN bus possible | B |
| GND | 5 | Device is unpowered and will not function | B |
| LIN | 6 | No LIN communication possible | B |
| VSUP | 7 | Device is unpowered and will not function | B |
| INH | 8 | Will not be able to enable system power if used in this manner | B |
Note: DRB package includes a thermal pad
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 |
|---|---|---|---|---|
| RXD | 1 | EN | Device will go into sleep mode when a dominant bit is received on the LIN bus, disabling communication | B |
| EN | 2 | WAKE | Absolute maximum voltage on EN pin may be exceeded causing damage to EN pin | A |
| WAKE | 3 | TXD | Absolute maximum voltage on EN pin may be exceeded causing damage to TXD pin | A |
| GND | 5 | LIN | LIN biased dominant, no LIN communication possible | B |
| LIN | 6 | VSUP | LIN biased recessive, no LIN communication possible | B |
| VSUP | 7 | INH | INH biased high, will not be able to turn off system power if used in this manner | B |
Note: The DRB package includes a thermal pad. There is a chance the thermal pad is
soldered down and could short to any pin on device. What the thermal pad is soldered
to determines the behavior. Example: if soldered to a ground plane then the adjacent
pins would behave as if shorted to ground.
Table 4-5 Pin FMA for Device Pins
Short-Circuited to VSUP supply
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| RXD | 1 | Absolute maximum voltage violation, transceiver may be damaged | A |
| EN | 2 | Absolute maximum voltage violation, transceiver may be damaged | A |
| WAKE | 3 | WAKE pin biased high and no local wake up possible | B |
| TXD | 4 | Absolute maximum voltage violation, transceiver may be damaged | A |
| GND | 5 | Device is unpowered and will not function | A |
| LIN | 6 | LIN biased recessive, no LIN communication possible | B |
| VSUP | 7 | None | D |
| INH | 8 | INH biased high, will not be able to turn off system power if used in this manner | B |
Note: DRB package includes a thermal pad