SFFS424 June 2022 TCAN1462-Q1 , TCAN1462V-Q1

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the TCAN1462-Q1 and TCAN1462V-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 V_CC (see Table 4-5)
Pin short-circuited to V_BAT (see Table 4-6)
Pin short-circuited to V_IO (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 TCAN1462-Q1 and TCAN1462V-Q1 SOIC pin diagram. Figure 4-2 shows the TCAN1462-Q1 and TCAN1462V-Q1 VSON pin diagram. Figure 4-3 shows the TCAN1462-Q1 and TCAN1462V-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TCAN1044A-Q1, TCAN1044AV-Q1 data sheet.

Figure 4-1 SOIC Pin Diagram

Figure 4-3 SOT Pin Diagram

Figure 4-2 VSON Pin Diagram

Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:

V_CC = 4.5 to 5.5 V
V_BAT = 6 to 24 V
V_IO = 1.7 to 5.5 V

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
V_CC	3	Device unpowered, high I_CC current.	B
RXD	4	RXD default is high side FET ON, with pin short to ground, it forms direct path between supply and ground causing high current	A
NC	5	None	D
V_IO	5	Device will be in protected mode. Transceiver passive on bus.	B
CANL	6	V_O(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
V_CC	3	Device unpowered.	B
RXD	4	No RXD output, unable to receive data.	B
NC	5	None	D
V_IO	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	V_CC	Device unpowered, high I_CCcurrent.	B
V_CC	3	RXD	RXD output stuck high, unable to receive data.	B
NC	5	CANL	None	D
V_IO	5	CANL	Bus stuck recessive, no communication possible. I_OS current may be reached on CANL.	B
CANL	6	CANH	Bus stuck recessive, no communication possible. I_OS 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 V_CC

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 I_CC current.	B
V_CC	3	None	D
RXD	4	RXD pin stuck high, unable to receive data.	B
NC	5	None	D
V_IO	5	IO pins will operate as 5V input/outputs. Microcontroller may be damaged if V_CC > V_IO.	C
CANL	6	RXD always recessive, no communication possible. I_OS current may be reached.	B
CANH	7	V_O(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 V_BAT

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 I_BAT current	B
V_CC	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
V_IO	5	Absolute maximum violation, transceiver may be damaged.	A
CANL	6	RXD always recessive, no communication possible. I_OS current may be reached.	B
CANH	7	V_O(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 V_IO

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 I_IO current.	B
V_CC	3	IO pins will operate as 5V input/outputs. Microcontroller may be damaged if V_CC > V_IO.	C
RXD	4	RXD pin stuck high, unable to receive data.	B
NC	5	None	D
V_IO	5	None	D
CANL	6	RXD always recessive, no communication possible. I_OS current may be reached is V_IO ≥ 3.3V.	B
CANH	7	V_O(REC) spec violated if V_IO ≥ 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 TCAN1462V-Q1 device.