TCAN1046-Q1 and TCAN1046V-Q1 Functional Safety FIT Rate, FMD and Pin FMA
- SFFS063 June 2021 TCAN1046-Q1 , TCAN1046V-Q1

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FUNCTIONAL SAFETY FIT RATE, FMD AND PIN-FMA

TCAN1046-Q1 and TCAN1046V-Q1 Functional Safety FIT Rate, FMD and Pin FMA

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1 Overview

This document contains information for TCAN1046-Q1 and TCAN1046V-Q1 (VSON package) to aid in a functional safety system design. Information provided are:

Functional Safety Failure In Time (FIT) rates of the semiconductor component estimated by the application of industry reliability standards
Component failure modes and their distribution (FMD) based on the primary function of the device
Pin failure mode analysis (Pin FMA)

Figure 1-1 shows the TCAN1046-Q1 functional block diagram for reference. Figure 1-2 shows the TCAN1046V-Q1 functional block diagram for reference.

Figure 1-1 TCAN1046-Q1 Functional Block Diagram

Figure 1-2 TCAN1046V-Q1 Functional Block Diagram

TCAN1046-Q1 and TCAN1046V-Q1 were developed using a quality-managed development process, but were not developed in accordance with the IEC 61508 or ISO 26262 standards.

2 Functional Safety Failure In Time (FIT) Rates

This section provides Functional Safety Failure In Time (FIT) rates for TCAN1046-Q1/TCAN1046V-Q1 based on two different industry-wide used reliability standards:

Table 2-1 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
Table 2-2 provides FIT rates based on the Siemens Norm SN 29500-2

Table 2-1 Component Failure Rates per IEC TR 62380 / ISO 26262 Part 11

FIT IEC TR 62380 / ISO 26262	FIT (Failures Per 10⁹ Hours) 14-pin VSON (DMT)
Total Component FIT Rate	9
Die FIT Rate	3
Package FIT Rate	6

The failure rate and mission profile information in Table 2-1 comes from the Reliability data handbook IEC TR 62380 / ISO 26262 part 11:

Mission Profile: Motor Control from Table 11
Power dissipation: 250 mW
Climate type: World-wide Table 8
Package factor (lambda 3): Table 17b
Substrate Material: FR4
EOS FIT rate assumed: 0 FIT

Table 2-2 Component Failure Rates per Siemens Norm SN 29500-2

Table	Category	Reference FIT Rate	Reference Virtual T_J
5	CMOS, BICMOS Digital, analog / mixed	20 FIT	55°C

The Reference FIT Rate and Reference Virtual T_J (junction temperature) in Table 2-2 come from the Siemens Norm SN 29500-2 tables 1 through 5. Failure rates under operating conditions are calculated from the reference failure rate and virtual junction temperature using conversion information in SN 29500-2 section 4.

3 Failure Mode Distribution (FMD)

The failure mode distribution estimation for TCAN1046-Q1 and TCAN1046V-Q1 in Table 3-1 comes from the combination of common failure modes listed in standards such as IEC 61508 and ISO 26262, the ratio of sub-circuit function size and complexity and from best engineering judgment.

The failure modes listed in this section reflect random failure events and do not include failures due to misuse or overstress.

Table 3-1 Die Failure Modes and Distribution

Die Failure Modes	Failure Mode Distribution (%)
Receiver Fail	45%
Transmitter Fail	45%
CANH or CANL driver stuck dominant	5%
Short circuit any two pins	5%

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the TCAN1046-Q1 and TCAN1046V-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 4-6)
Pin short-circuited to VIO (see Table 4-7)
Pin short-circuited to VBAT (see Table 4-8)

Table 4-2 through Table 4-8 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 TCAN1046-Q1 pin diagram , and Figure 4-2 shows the TCAN1046V-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TCAN1046-Q1/TCAN1046V-Q1 data sheet.

Figure 4-1 TCAN1046-Q1 Pin Diagram

Figure 4-2 TCAN1046V-Q1 Pin Diagram

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

VCC = 4.5 to 5.5V
VIO (if applicable) = 1.7 to 5.5V

Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground

Pin Name	Pin No. (TCAN1046-Q1)	Pin No. (TCAN1046V-Q1)	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	1	CAN1 will enter dominant time out mode. Unable to transmit data to the CAN1 bus.	B
GND1	2	2	None	D
VCC1	3	-	CAN1 unpowered, high I_CC current.	B
VCC	-	3	Device unpowered, high I_CC current.	B
RXD1	4	4	Internal damage possible, MCU may not be able to receive data from the RXD pin. Unable to receive data from CAN1 bus.	A
TXD2	5	6	CAN2 will enter dominant time out mode. Unable to transmit data to the CAN2 bus.	B
GND2	6	5	None	D
VCC2	7	-	CAN2 unpowered, high I_CC current.	B
RXD2	8	7	Internal damage possible, MCU may not be able to receive data from the RXD pin. Unable to receive data from CAN2 bus.	A
CANL2	9	9	V_O(REC) spec violated. Degraded EMC performance on CAN2 bus.	C
CANH2	10	10	Device cannot drive dominant to CAN2 bus, no communication possible.	B
STB2	11	8	STB2 stuck low, CAN2 bus unable to enter low-power mode.	B
VIO	-	11	Device will be in protected mode. Transceiver passive on both CAN1 and CAN2 bus.	B
CANL1	12	12	V_O(REC) spec violated. Degraded EMC performance on CAN1 bus.	C
CANH1	13	13	Device cannot drive dominant to CAN1 bus, no communication possible.	B
STB1	14	14	STB1 stuck low, CAN1 bus unable to enter low-power mode.	B
Thermal Pad	-	-	None	D

Table 4-3 Pin FMA for Device Pins Open-Circuited

Pin Name	Pin No. (TCAN1046-Q1)	Pin No. (TCAN1046V-Q1)	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	1	TXD1 pin defaults high, CAN1 bus state always recessive and unable to transmit data to CAN1 bus.	B
GND1	2	2	CAN1 unpowered.	B
VCC1	3	-	CAN1 unpowered.	B
VCC	-	3	Device unpowered.	B
RXD1	4	4	No RXD1 output, unable to receive data from CAN1 bus.	B
TXD2	5	6	TXD2 pin defaults high, CAN2 bus state always recessive and unable to transmit data to CAN2 bus.	B
GND2	6	5	CAN2 unpowered.	B
VCC2	7	-	CAN2 unpowered.	B
RXD2	8	7	No RXD2 output, unable to receive data from CAN2 bus.	B
CANL2	9	9	Device cannot drive dominant on CAN2 bus, unable to communicate.	B
CANH2	10	10	Device cannot drive dominant on CAN2 bus, unable to communicate.	B
STB2	11	8	STB2 pin defaults high, CAN2 portion stuck in low-power mode.	B
VIO	-	11	Device will be in protected mode, Transceiver passive on both CAN1 and CAN2 bus.	B
CANL1	12	12	Device cannot drive dominant on CAN1 bus, unable to communicate.	B
CANH1	13	13	Device cannot drive dominant on CAN1 bus, unable to communicate.	B
STB1	14	14	STB1 pin defaults high, CAN1 portion stuck in low-power mode.	B
Thermal Pad	-	-	None	D

Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin TCAN1046-Q1

Pin Name	Pin No.	Shorted to	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	GND1	CAN1 bus will enter dominant time out mode. Unable to transmit data to CAN1 bus.	B
GND1	2	VCC1	CAN1 unpowered, high I_CC current.	B
VCC1	3	RXD1	RXD1 output stuck high, unable to receive data from CAN1 bus.	B
RXD1	4	TXD2	RXD1 output reflects the input to TXD2, a separate CAN transceiver. Information from CAN1 will not be received correctly.	B
TXD2	5	GND2	CAN2 bus will enter dominant time out mode. Unable to transmit data to CAN2 bus.	B
GND2	6	VCC2	CAN2 unpowered, high I_CC current.	B
RXD2	8	CANL2	Messages on RXD2 will be corrupted by CANL2. Reception of data from CAN2 bus will not be possible. I_OS current may be reached.	B
CANL2	9	CANH2	CAN2 bus stuck recessive, no communication possible. I_OS current may be reached.	B
CANH2	10	STB2	CAN2 driver and receiver turn off when a dominant is driven on CAN2 bus. May not enter normal mode.	B
STB2	11	CANL1	CAN2 driver and receiver may turn off when the CAN1 bus is recessive. May not enter normal mode.	B
CANL1	12	CANH1	CAN1 bus stuck recessive, no communication possible I_OS current may be reached.	B
CANH1	13	STB1	CAN1 driver and receiver turn off when a dominant is driven on CAN1 bus. 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 Adjacent Pin TCAN1046V-Q1

Pin Name	Pin No.	Shorted to	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	GND1	CAN1 bus will enter dominant time out mode. Unable to transmit data to CAN1 bus.	B
GND1	2	VCC	Device unpowered, high I_CC current.	B
VCC	3	RXD1	RXD1 output stuck high, unable to receive data from CAN1 bus.	B
RXD1	4	GND2	CAN1 receiver output stuck dominant. Unable to receive data from CAN1 bus.	B
GND2	5	TXD2	CAN2 bus will enter dominant time out mode. Unable to transmit data to CAN2 bus.	B
TXD2	6	RXD2	RXD2 output reflects the input to TXD2, and while this is the same transceiver, due to loop delay, the communication will be corrupted. Information from CAN2 bus will not be received correctly.	B
STB2	8	CANL2	CAN2 driver and receiver may turn off when the CAN2 bus is recessive. May not enter normal mode.	B
CANL2	9	CANH2	CAN2 bus stuck recessive, no communication possible. I_OS current may be reached.	B
CANH2	10	VIO	CAN2 bus stuck dominant, no communication possible.	B
VIO	11	CANL1	CAN1 bus stuck recessive, no communication possible. I_OS current may be reached on CANL1.	B
CANL1	12	CANH1	CAN1 bus stuck recessive, no communication possible I_OS current may be reached.	B
CANH1	13	STB1	CAN1 driver and receiver turn off when a dominant is driven. May not enter normal mode.	B

Table 4-6 Pin FMA for Device Pins Short-Circuited to VCC

Pin Name	Pin No. (TCAN1046-Q1)	Pin No. (TCAN1046V-Q1)	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	1	TXD1 pin stuck high, unable to transmit data to CAN1 bus.	B
GND1	2	2	CAN1 transceiver unpowered, high I_CC current.	B
VCC1	3	-	None	D
VCC	-	3	None	D
RXD1	4	4	RXD1 pin stuck high, unable to receive data from CAN1 bus.	B
TXD2	5	6	TXD2 pin stuck high, unable to transmit data to CAN2 bus.	B
GND2	6	5	CAN2 transceiver unpowered, high I_CC current.	B
VCC2	7	-	None	D
RXD2	8	7	RXD2 pin stuck high, unable to receive data for CAN2 bus.	B
CANL2	9	9	CAN2 bus always recessive, no communication possible. I_OS current may be reached.	B
CANH2	10	10	V_O(REC) spec violated, degraded EMC performance on CAN2 bus.	C
STB2	11	8	STB2 stuck high, CAN2 transceiver always in standby mode.	B
VIO	-	11	IO pins will operate as 5V input/output. Microcontroller may be damaged if VCC > VIO.	C
CANL1	12	12	CAN1 bus always recessive, no communication possible. I_OS current may be reached.	B
CANH1	13	13	V_O(REC) spec violated, degraded EMC performance on CAN1 bus.	C
STB1	14	14	STB1 stuck high, CAN1 transceiver always in standby mode.

Table 4-7 PIN FMA for Device Pins Short-Circuited to VIO

Pin Name	Pin No. (TCAN1046V-Q1)	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	TXD1 stuck high, unable to transmit data to CAN1 bus.	B
GND1	2	CAN1 unpowered, high I_IO current.	B
VCC	3	IO pins will operate as 5V input/output. Microcontroller may be damaged if VCC > VIO.	C
RXD1	4	RXD1 pin stuck high, unable to receive data from CAN1 bus.	B
GND2	5	CAN2 unpowered, high I_IO current.	B
TXD2	6	TXD2 stuck high, unable to transmit data to CAN2 bus.	B
RXD2	7	RXD2 pin stuck high, unable to receive data from CAN2 bus.	B
STB2	8	STB2 stuck high, CAN2 transceiver always in standby mode.	B
CANL2	9	CAN2 bus always recessive, no communication possible. I_OS current may be reached if VIO ≥ 3.3V.	B
CANH2	10	V_O(REC) spec violated if VIO ≥ 3.3V, degraded EMC performance on CAN2 bus.	C
VIO	11	None	D
CANL1	12	CAN1 bus always recessive, no communication possible. I_OS current may be reached if VIO ≥ 3.3V.	B
CANH1	13	V_O(REC) spec violated if VIO ≥ 3.3V, degraded EMC performance on CAN1 bus.	C
STB1	14	STB1 stuck high, CAN1 transceiver always in standby mode.	B

Table 4-8 Pin FMA for Device Pins Short-Circuited to VBAT

Pin Name	Pin No. (TCAN1046-Q1)	Pin No. (TCAN1046V-Q1)	Description of Potential Failure Effect(s)	Failure Effect Class
TXD1	1	1	Absolute maximum violation, transceiver may be damaged. Unable to transmit data to CAN1 bus.	A
GND1	2	2	Device unpowered, high I_BAT current.	B
VCC1	3	-	Absolute maximum violation, transceiver may be damaged. CAN1 bus may be unable to communicate.	A
VCC	-	3	Absolute maximum violation, transceiver may be damaged. CAN bus may be unable to communicate.	A
RXD1	4	4	Absolute maximum violation, transceiver may be damaged. Unable to receive data from CAN1 bus.	A
TXD2	5	6	Absolute maximum violation, transceiver may be damaged. Unable to transmit data to CAN2 bus.	A
GND2	6	5	Device unpowered, high I_BAT current.	B
VCC2	7	-	Absolute maximum violation, transceiver may be damaged. CAN2 bus may be unable to communicate.	A
RXD2	8	7	Absolute maximum violation, transceiver may be damaged. Unable to receive data from CAN2 bus.	B
CANL2	9	9	CAN2 bus always recessive, no communication possible. I_OS current may be reached.	B
CANH2	10	10	V_O(REC) spec violated, degraded EMC performance on CAN2 bus.	C
STB2	11	8	Absolute maximum violation, transceiver may be damaged. CAN2 transceiver stuck in standby mode.	A
VIO	-	11	Absolute maximum violation, transceiver may be damaged.	A
CANL1	12	12	CAN1 bus always recessive, no communication possible. I_OS current may be reached.	B
CANH1	13	13	V_O(REC) spec violated, degraded EMC performance on CAN1 bus.	B
STB1	14	14	Absolute maximum violation, transceiver may be damaged. CAN1 transceiver stuck in standby mode.	A

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