SLLA503 October 2020 TCAN1044-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the TCAN1044-Q1 and TCAN1044V-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 VBAT (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 TCAN1044-Q1/TCAN1044V-Q1 SOIC pin diagram. Figure 4-2 shows the TCAN1044-Q1/TCAN1044V-Q1 VSON pin diagram. Figure 4-3 shows the TCAN1044-Q1/TCAN1044V-Q1 SOT pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TCAN1044-Q1/TCAN1044V-Q1 data sheet.
Figure 4-1 SOIC Pin Diagram
Figure 4-2 VSON Pin Diagram
Figure 4-3 SOT Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- VCC = 4.5 to 5.5V
- VBAT = 6 to 24V
- VIO = 1.7 to 5.5V
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 |
|---|---|---|---|
| TXD | 1 | Device will enter dominant time out mode. Unable to transmit data. | B |
| GND | 2 | None | D |
| VCC | 3 | Device unpowered, high ICC current. | B |
| RXD | 4 | Transceiver output stuck dominant. Unable to receive data. | B |
| NC | 5 | None | D |
| VIO | 5 | Device will be in protected mode. Transceiver passive on bus. | B |
| CANL | 6 | VO(REC) spec violated. Degraded EMC performance. | C |
| CANH | 7 | Device cannot drive dominant to the bus, no communication possible. | B |
| STB | 8 | STB stuck low, transceiver unable to enter low-power mode. | 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 Effect(s) | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD pin defaults high, device always recessive and unable to transmit data. | B |
| GND | 2 | Device unpowered. | B |
| VCC | 3 | Device unpowered. | B |
| RXD | 4 | No RXD output, unable to receive data. | B |
| NC | 5 | None | D |
| VIO | 5 | Device will be in protected mode. Transceiver passive on bus. | B |
| CANL | 6 | Device cannot drive dominant on the bus, unable to communicate. | B |
| CANH | 7 | Device cannot drive dominant on the bus, unable to communicate. | B |
| STB | 8 | STB pin defaults high, transceiver stuck in low-power mode. | 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 Effect(s) | Failure Effect Class |
|---|---|---|---|---|
| TXD | 1 | GND | Device will enter dominant time out mode. Unable to transmit data. | B |
| GND | 2 | VCC | Device unpowered, high ICCcurrent. | B |
| VCC | 3 | RXD | RXD output stuck high, unable to receive data. | B |
| NC | 5 | CANL | None | D |
| VIO | 5 | CANL | Bus stuck recessive, no communication possible. IOS current may be reached on CANL. | B |
| CANL | 6 | CANH | Bus stuck recessive, no communication possible. IOS current may be reached on CANH/CANL. | B |
| CANH | 7 | STB | Driver and receiver turn off when a dominant is driven. May 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 Effect(s) | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD stuck high, unable to transmit data. | B |
| GND | 2 | Device unpowered, high ICC current. | B |
| VCC | 3 | None | D |
| RXD | 4 | RXD pin stuck high, unable to receive data. | B |
| NC | 5 | None | D |
| VIO | 5 | IO pins will operate as 5V input/outputs. Microcontroller may be damaged if VCC > VIO. | C |
| CANL | 6 | RXD always recessive, no communication possible. IOS current may be reached. | B |
| CANH | 7 | VO(REC) spec violated, degraded EMC performance. | C |
| STB | 8 | STB stuck high, transceiver always in standby mode. | B |
Table 4-6 Pin FMA for Device Pins Short-Circuited to
VBAT
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | Absolute maximum violation, transceiver may be damaged. Unable to transmit data. | A |
| GND | 2 | Device unpowered, high IBAT current | B |
| VCC | 3 | Absolute maximum violation, transceiver may be damaged. Bus may be unable to communicate. | A |
| RXD | 4 | Absolute maximum violation, transceiver may be damaged. Unable to receive data. | A |
| NC | 5 | None | D |
| VIO | 5 | Absolute maximum violation, transceiver may be damaged. | A |
| CANL | 6 | RXD always recessive, no communication possible. IOS current may be reached. | B |
| CANH | 7 | VO(REC) spec violated, degraded EMC performance. | C |
| STB | 8 | Absolute maximum violation, transceiver may be damaged. Transceiver stuck in low-power mode. | A |
Table 4-7 Pin FMA for Device Pins Short-Circuited to VIO
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| TXD | 1 | TXD stuck high, unable to transmit data. | B |
| GND | 2 | Device unpowered, high IIO current. | B |
| VCC | 3 | IO pins will operate as 5V input/outputs. Microcontroller may be damaged if VCC > VIO. | C |
| RXD | 4 | RXD pin stuck high, unable to receive data. | B |
| NC | 5 | None | D |
| VIO | 5 | None | D |
| CANL | 6 | RXD always recessive, no communication possible. IOS current may be reached is VIO ≥ 3.3V. | B |
| CANH | 7 | VO(REC) spec violated if VIO ≥ 3.3V, degraded EMC performance. | C |
| STB | 8 | STB stuck high, transceiver always in standby mode. | B |
Note:
Table 4-7 is only applicable to the TCAN1044V-Q1 device.