SFFS953 December 2024 TCAN1043N-Q1 , TCAN1473-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the TCAN1043N-Q1 and TCAN1473-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 VCC (see Table 4-5)
- Pin short-circuited to VSUP (see Table 4-6)
- Pin short-circuited to VIO (Table 4-7)
Table 4-2 through Table 4-7 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 SOIC (D) pin diagram. Figure 4-2 shows the VSON (DMT) pin diagram. Figure 4-3 shows the SOT (DYY) pin diagram.
For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TCAN1043N-Q1 and TCAN1473-Q1 data sheets.
Figure 4-1 SOIC (D) Pin Diagram
Figure 4-2 VSON (DMT) Pin Diagram
Figure 4-3 SOT
(DYY) Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- VCC = 4.5V to 5.5V
- VSUP = 4.5V to 40V
- VIO = 1.7V to 5.5V
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD biased dominant indefinitely. The device enters dominant time-out mode. Unable to transmit data. | B |
| GND | 2 | None. | D |
| VCC | 3 | Device enters Sleep mode. There is a high current draw from the external regulator that supplies to the VCC pin. | B |
| RXD | 4 | Receiver output biased recessive indefinitely. The host is unable to receive data from the bus. | B |
| VIO | 5 | Device enters Sleep mode. Transceiver is passive on bus. There is a high current draw from the external regulator that supplies to VIO. | B |
| EN | 6 | EN pin biased low. The device is not able to enter normal mode. Unable to communicate. | B |
| INH | 7 | High ISUP current, the INH pin can be damaged and indication from sleep mode transition is not available. | A |
| nFAULT | 8 | nFAULT pin biased low indefinitely, which indicates a fault indefinitely. | B |
| WAKE | 9 | WAKE pin biased low indefinitely and is not able to utilize the local wake-up function. | B |
| VSUP | 10 | Device is not powered. There will be a high current flowing from the source supplying to the VSUP pin (battery) to the ground. | B |
| NC | 11 | None. | D |
| CANL | 12 | VO(REC) specification is violated, degraded EMC performance. | C |
| CANH | 13 | Device cannot drive dominant bit to the bus, no communication possible. | B |
| nSTB | 14 | nSTB biased low indefinitely. The transceiver is unable to enter normal mode. Unable to communicate. | B |
| Thermal Pad | - | None. | D |
Note: The VSON package includes a thermal pad.
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD pin defaults to a recessive bias. The device is always recessive and unable to transmit data. | B |
| GND | 2 | Device is not powered. | B |
| VCC | 3 | Device is in protected mode. | B |
| RXD | 4 | No RXD output, unable to receive data. | B |
| VIO | 5 | Device is in protected mode. | B |
| EN | 6 | EN pin defaults to a logic-low bias. The device is not able to enter normal mode. Unable to communicate. | B |
| INH | 7 | None. | D |
| nFAULT | 8 | No effect on the device performance, unable to monitor system faults. | B |
| WAKE | 9 | No effect on the device performance, unable to use the local wake-up function. | B |
| VSUP | 10 | Device is not powered. | B |
| NC | 11 | None. | D |
| CANL | 12 | Device cannot drive dominant on bus and is unable to communicate. | B |
| CANH | 13 | Device cannot drive dominant on bus and is unable to communicate. | B |
| nSTB | 14 | nSTB defaults to a logic-low bias. The device is not able to enter normal mode. Unable to communicate. | B |
| Thermal Pad | - | None. | D |
Note: The VSON 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 Effects | Failure Effect Class |
|---|---|---|---|---|
| TXD | 1 | GND | TXD is biased dominant indefinitely. The device enters dominant time-out mode. Unable to transmit data. | B |
| GND | 2 | VCC | Device is in protected mode, high ICC current. | B |
| VCC | 3 | RXD | RXD output biased recessive indefinitely. The controller is unable to receive data from CAN bus. | B |
| RXD | 4 | VIO | RXD output biased recessive indefinitely. The controller is unable to receive data from CAN bus. | B |
| VIO | 5 | EN | EN pin biased high indefinitely. The device is unable to enter standby and silent mode. | B |
| EN | 6 | INH | Absolute maximum violation on the EN pin, except in sleep mode. Transceiver can be damaged. | A |
| nFAULT | 8 | WAKE | Potential absolute maximum violation on nFAULT pin if WAKE is biased high. Transceiver can be damaged. | A |
| WAKE | 9 | VSUP | WAKE biased high indefinitely, unable to utilize the local wake-up function. | B |
| VSUP | 10 | NC | None. | D |
| NC | 11 | CANL | None. | D |
| CANL | 12 | CANH | Bus biased recessive. No communication is possible. IOS current can be reached on CANH/CANL. | B |
| CANH | 13 | nSTB | Driver and receiver turn off when the CAN bus is recessive. Potentially does not enter normal mode. | B |
Note: The VSON package includes a thermal pad. All device pins are adjacent to the thermal pad. The device behavior when pins are shorted to the thermal pad depends on which net is connected to the thermal pad.
Table 4-5 Pin FMA for Device Pins Short-Circuited to VCC
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD biased recessive indefinitely, unable to transmit data. | B |
| GND | 2 | CAN transmitter is not powered and the device enters Sleep mode. There is a high current draw from the external regulator supplying to the VCC pin. | B |
| VCC | 3 | None. | D |
| RXD | 4 | Receiver output biased recessive indefinitely. Host is unable to receive data from bus. | B |
| VIO | 5 | I/O pins operate as 5V inputs and outputs. Microcontroller can be damaged if VCC > VIO. | C |
| EN | 6 | EN biased high indefinitely. The device is unable to enter standby and silent mode. | B |
| INH | 7 | Absolute maximum violation on VCC pin. INH is biased at VCC voltage. System potentially does not wake up. | A |
| nFAULT | 8 | nFAULT biased high indefinitely. The transceiver is unable to report faults. | B |
| WAKE | 9 | None. | D |
| VSUP | 10 | Absolute maximum violation on VCC. | A |
| NC | 11 | None. | D |
| CANL | 12 | IOS current can be reached, RXD is always recessive. | B |
| CANH | 13 | VO(REC) specification is violated, degraded EMC performance. | C |
| nSTB | 14 | nSTB biased high indefinitely. The transceiver is unable to enter standby and sleep mode. | B |
Table 4-6 Pin FMA for Device Pins Short-Circuited to VSUP
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | Absolute maximum violation, transceiver can be damaged. | A |
| GND | 2 | Device is not powered, high ISUP current. | B |
| VCC | 3 | Absolute maximum violation, transceiver can be damaged. | A |
| RXD | 4 | Absolute maximum violation, transceiver can be damaged. | A |
| VIO | 5 | Absolute maximum violation, transceiver can be damaged. | A |
| EN | 6 | Absolute maximum violation, transceiver can be damaged. | A |
| INH | 7 | Minimal current driven into the INH pin. | D |
| nFAULT | 8 | Absolute maximum violation, transceiver can be damaged. | A |
| WAKE | 9 | WAKE biased high, unable to use the local wake-up function. | B |
| VSUP | 10 | None. | D |
| NC | 11 | None. | D |
| CANL | 12 | IOS current can be reached. RXD is always recessive. | B |
| CANH | 13 | VO(REC) specification is violated, degraded EMC performance and communication errors can also result. | C |
| nSTB | 14 | Absolute maximum violation, transceiver can be damaged. | A |
Table 4-7 Pin FMA for Device Pins Short-Circuited to VIO
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD biased recessive indefinitely, unable to transmit data. | B |
| GND | 2 | Device is not powered. There is a high current draw from the external regulator supplying to the VIO pin. | B |
| VCC | 3 | I/O pins operate as 5V inputs and outputs. Microcontroller can be damaged if VCC > VIO. | C |
| RXD | 4 | Receiver output biased recessive indefinitely. Host is unable to receive data from bus. | B |
| VIO | 5 | None. | D |
| EN | 6 | EN biased high indefinitely. The device is unable to enter standby and silent mode. | B |
| INH | 7 | Absolute maximum violation on the VIO pin. INH is biased at VIO voltage. System potentially does not wake up. | A |
| nFAULT | 8 | nFAULT biased high indefinitely. The transceiver is unable to report faults. | B |
| WAKE | 9 | None. | D |
| VSUP | 10 | Absolute maximum violation on VIO. | A |
| NC | 11 | None. | D |
| CANL | 12 | IOS current can be reached, RXD is always recessive. | B |
| CANH | 13 | VO(REC) specification is violated, degraded EMC performance. | C |
| nSTB | 14 | nSTB biased high indefinitely. The transceiver is unable to enter standby and sleep mode. | B |