TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-Q1 Functional Safety FIT Rate, FMD, and Pin FMA

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1 Overview

This document contains information for TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-Q1. These are Controller Area Network (CAN) transceivers. The TCAN1044A-Q1 and TCAN1044AV-Q1 come in the SOIC (D), VSON (DRB), and SOT (DDF) packages to aid in a functional safety system design. The TCAN1044AEV-Q1 comes in the SOIC (D) and SOT (DDF) packages to aid in 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 (FMA) for the device pins of TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-Q1

#GUID-E488EBD4-511E-41B0-B770-91A9719CA4DD shows the device functional block diagram for reference. TCAN1044AV-Q1 and TCAN1044AEV-Q1 have the V_IO input at pin 5, while TCAN1044A-Q1 has a no connect (NC) at pin 5.

Figure 1-1 TCAN1044A-Q1, TCAN1044AV-Q1, TCAN1044AEV-Q1 Functional Block Diagram

TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-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 TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-Q1 based on two different industry-wide used reliability standards:

#GUID-E0AE5370-5A0E-4343-9E17-61DD7474D016/GUID-D2F32BF7-F0F2-45BD-945E-5E9A117DF52F provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
#GUID-E0AE5370-5A0E-4343-9E17-61DD7474D016/GUID-F6448F76-6F1A-4872-8629-AFB15459B793 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) 8-pin SOIC (D)	FIT (Failures Per 10⁹ Hours) 8-pin VSON (DRB)	FIT (Failures Per 10⁹ Hours) 8-pin SOT (DDF)
Total Component FIT Rate	10	7	5
Die FIT Rate	3	3	3
Package FIT Rate	7	4	2

The failure rate and mission profile information in #GUID-E0AE5370-5A0E-4343-9E17-61DD7474D016/GUID-D2F32BF7-F0F2-45BD-945E-5E9A117DF52F comes from the reliability data handbook IEC TR 62380 / ISO 26262 part 11:

Mission Profile: Motor Control from Table 11
Power dissipation: 130 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 ASICs Analog & Mixed =<50V supply	20 FIT	55C

The Reference FIT Rate and Reference Virtual T_J (junction temperature) in #GUID-E0AE5370-5A0E-4343-9E17-61DD7474D016/GUID-F6448F76-6F1A-4872-8629-AFB15459B793 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 TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-Q1 in #GUID-143C3C74-D6D8-4132-B189-EFDF100BCD53/GUID-0D4C59FF-05DC-486D-BF82-73817190B27B 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%
CANL or CANH 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 TCAN1044A-Q1, TCAN1044AV-Q1, and TCAN1044AEV-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

#GUID-59B67224-3CC4-4810-AE39-411866CAB6F7 shows the TCAN1044A-Q1/TCAN1044AV-Q1/TCAN1044AEV-Q1 SOIC pin diagram. #FIG_VVB_MNB_PMB shows the TCAN1044A-Q1/TCAN1044AV-Q1 VSON pin diagram. #FIG_T3Q_NNB_PMB shows the TCAN1044A-Q1/TCAN1044AV-Q1/TCAN1044AEV-Q1 SOT 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 and TCAN1044AEV-Q1 data sheets.

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 TCAN1044AV-Q1/TCAN1044AEV-Q1 device.