Circuit Protection Automotive Applications Guide

TransGuard
®
Automotive Series
CIRCUIT PROTECTION IN AUTOMOTIVE
APPLICATIONS
The following applications and schematic diagrams show where
TransGuards® might be used to suppress various transient voltages:
• Automotive Transients
• LIN Bus
• CAN Bus and FlexRay
• Electric Power Steering
• Seat Motor Circuit
• LED Door Lamp
• Drive by Wire
• Keyless Entry
• Voltage Regulator
• Bluetooth
• LED Driver
114
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
AUTOMOTIVE TRANSIENTS
AVX MULTILAYER VARISTORS
Todays automobiles are using new technologies based on
electronics systems connected by wide variety of networks
to provide increased safety, convenience and comfort, to
reduce emissions, increase fuel efficiency and more.
The EMC requirements of today’s automotive electronics are a natural fit for
the use of AVX MultiLayer Varistors (MLVs).
AVX AUTOMOTIVE VARISTORS ADVANTAGES
During the lifetime these systems are subjected to many
overvoltage transient surges. To ensure safe and reliable
function it is necessary to protect these sensitive systems
againts overvoltage surges.
• AEC-Q200 qualified
• Bi-directional protection
• Compact footprint
• Very fast response - sub ns
Automotive Power Rail Transients
• EMI/RFI filtering in the off state
The transients on automotive power rails are usually medium
to high energy transients and are caused by engine start
such as Jump start (connecting other cars battery to jump
start the engine), Load Dump (sudden load disconnect from
alternator) or inductive switching (caused by DC motors
on/off switching - e.g. window lifter, wipers, adaptive
headlights). These transients are typically bi-directional.
±25kV Air Discharge
±8kV HBM
2kV Charge
Device Model
800V Machine
Model
Nominal Voltage
• Multiple strikes capability
• No derating over operating temperature range
(-55°C to +125°C, 150°C available)
• RoHS compliant
• Optional hybrid termination (Pd/Ag) available
AVX Automotive Series Varistors provide reliable protection
against automotive related transients - such as Load Dump,
Jump Start and ESD to protect the growing number of
electronics systems used in automotive applications.
Transient examples:
• Load dump (ISO 7637-2-5)
• Jump Start
• ISO 7637 Pulse 1-3
• IEC 61000-4-2, etc.
0V
Automotive Data Line Transients
Data lines connecting the automotive systems need to be
protected against varisous ESD pulses to ensure sensitive
electronics protection. These transients are mainly caused
by human interaction with the electronics systems (controls,
buttons, ports) or by interaction between systems due to
different charge build up. These transients are typically bidirectional and very fast.
Load Dump
87V
Voltage Spikes
+100/-150V
+/-25kV ESD
Spikes
• AEC-Q200-002
• ISO 10605
• ISO 16750-2
• CI-220
• CI-260
The parts offer fast turn on time, bi-directional protection,
excellent multiple strikes capability and in addition also
EMI/RFI filtering in the off-state that can improve overall
system EMC performance.
High power MLV designs have been revised and miniaturized
to allow efficient protection of today’s most widely used
communication bus designs.
When used in communication bus designs, MLVs can save
approximately 90% of the board area involved with
diode/EMC cap solutions. In addition, MLVs offer a FIT rate
<0.1, an ability to be used at temperatures up to 150°C and
a fast turn on time.
MultiLayer Varistors (MLVs)
BUS
XCVR
TVS Diodes
BUS
XCVR
24V Jump Start
EMC
CAP
Nominal Voltage
0V
Reverse Battery
MLV PROTECTION METHOD
SINGLE COMPONENT SOLUTION
DIODE PROTECTION METHOD
THREE COMPONENT SOLUTION
TVS & EMI
TVS + EMI
115
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
MLVs have traditionally been used in inductively generated
automotive transient suppression applications such as
motors, relays and latches. MLVs offer a large in rush current
capability in a small package, high-energy transient
suppression and a broad and definable off state bulk EMC
capacitance. These, coupled with an extremely low FIT rate
and excellent process capability makes MLVs a common
device in today’s intermediate to high power automotive
circuit protection.
AUTOMOTIVE COMMUNICATION BUS
AVX varistors are indeal choice for automotive circuit
protection thanks to wide range of automotive qualified parts
covering wide range of applications from low capacitance
components for high speed data lines/RF circuits up to high
energy varistors for load dump and jump start requirements
on power lines or low speed data lines such as LIN Bus. AVX
also offers automotive varistors for targeted and enhanced
EMI filtering that help to improve overall EMC system
performance.
Automotive electronic systems are connected by various
network systems depending on the data speed
requirements. Most common networks include:
LIN (LOCAL INTERCONNECT
NETWORK)
LIN Bus operates at slower data speeds up to 20kbps and
provides reliable low cost automotive networking. Typical
applications are e.g. window lifter, door lock, seat controls,
mirror controls, wipers, rain sensors etc.
CAN (CONTROLLER AREA NETWORK)
CAN Bus is is a vehicle bus standard designed to allow
microcontrollers and devices to communicate with each
other within a vehicle without a host computer. CAN Bus
supports data speeds up to 1Mbps. Typical applications are
ECU connection to transmission, door locks, adaptive
headlights, climate control, etc.
MOST (MEDIA ORIENTED SYSTEMS
TRANSPORT)
MOST is standard for high-bandwidth automotive multimedia
networking. This network provides excellent Quality of
Service and seamless connectivity for audio/video streaming
through variety of multimedia interfaces such as DVD player,
head set, voice control.
116
FLEXRAY
FlexRay is an automotive network communications protocol
to govern on-board automotive computing. It is designed to
be faster and more reliable than CAN and TTP intended for
drive-by-wire applications.
Example of suitable AVX series based on data speed
and line type is shown below:
SERIES
Sub pF AntennaGuard Automotive Series
AG/Sub pF AG Automotive Series,
Miniature AC
FlexRay
CAN, FlexRay, AG Series
TransGuard® Automotive Series,
StaticGuard Automotive Series,
Radial Varistor
TransGuard® Automotive Series,
StaticGuard Automotive Series,
Radial Varistor, Miniature MAC,
TransFeed Automotive Series
TransFeed Automotive Series,
Controlled Capacitance
BUS
HDMI
1394a
MOST
TTP
FlexRay
TTCAN
CAN
Safe-by-Wire
DATA SPEED
3.2 Gbps
400 Mbps
45 Mbps
25 Mbps
10 Mbps
1 Mbps
1 Mbps - 50 Kbps
150 Kbps
LIN
<20 Kbps
High Speed
Data
Low Speed
ALL
Power Line
10-100 Mbps
Cutoff Frequency
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
LIN BUS
Car Battery
LIN BUS
1N4001
Ignition
Slave
ECU
C4
V BAT
V IN
C5
Voltage
Regulator
NCV8502
V OUT
C1
10k
Reset
C3
C6
+
C2
2.7k
V CC
VS
μP
GND
Component
V1
Product
Multilayer Varistor
BUS
NCV7360
TxD
GND
AVX Part number
VCAS080518C400RP
V1
ECU Connector
to Single Wire
LIN BUS
RxD
Specification
0805, 18Vdc, 0.3J, 120A, 550pF typ
117
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
CAN BUS
C1
Module
Connector
V CC
TxD
CAN_H
R1
Split
R2
Vcc
RxD
CAN_L
TX
D
Transceiver
Component
V1, V2
(V1+V2)
V1
Product
Multilayer Varistor
Multilayer Varistor
V2
C2
AVX Part number
CAN0001RP
CAN0002RP
Specification
0603, 18Vdc, 0.015J, 4A, 22pF max
0405 Dual Array, 0.015J, 4A, 22pF max
FLEXRAY
V CC
BP
ECU
BM
V1
Component
V1, V2
118
Product
Multilayer Varistor
V2
AVX Part number
FLX0005WP
Specification
0402, 18Vdc, 0.02J, 4A, 17pF max
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
ELECTRIC POWER STEERING
L1
C3
BAS21 D4
CSNS
TEMP
BN
INHS
FS
INLS
CONF
OCLS
DLS
GLS
SR
33k
+
470μF
VPWR_F
PS
V1
VPWR
OUT
PS_PWR_OUT
OUT
PS
GND
C1
C2
Component
V1
Product
Multilayer Varistor
TF1001L-2 D3
AVX Part number
VCAS121018J390RP
PS_PWR_RTN
PS
Specification
1210, 18Vdc, 1.5J, 500A, 3100pF typ
119
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
SEAT MOTOR CIRCUIT
V CC
DIR_1
Q1
C1 +
Q2
DIR_2
ROT_1
USER
V2
CONTROLLER
M
V1
SEAT
MOTOR
ROT_2
EN_1
Q4
Q3
FEEDBACK
SENSOR
EN_2
FB
Component
V1
V2
Product
Multilayer Varistor
Multilayer Varistor
AVX Part number
VCAS040218X400WP
VCAS121018J390RP
Specification
0402, 18Vdc, 0.05J, 20A, 65pF typ
1210, 18Vdc, 1.5J, 500A, 3100 pF typ
AVX Part number
VCAS120618D400RP
Specification
1206, 18Vdc, 0.4J, 150A, 900pF typ
LED DOOR LAMP
V1
Component
V1
120
Product
Multilayer Varistor
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
DRIVE BY WIRE – THROTTLE
ECU
Power Control Chip
VDD1
Supply Voltage
PAAT
C4
VCCPAAT
C1
V1
Supply
Voltage
C2
VDD2
Vreg
V2
Throttle
Drive
C3
VCC
C7
C5
C8
V4
C6 +
Accelerator
Sensor
V3
CLK-
Throttle
Sensor
CLK+
XTAL 13MHz
Component
V1, V2
V3, V4
Product
Multilayer Varistor
TransFeed
AVX Part number
VCAS080518C400DP
V2AF118X500Y3DDP
Specification
0805, 18Vdc, 0.3J, 120A, 550pF typ
0805, 18Vdc, 0.05J, 20A, 75pF typ
121
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
KEYLESS ENTRY
Vehicle
ID Device
Up-link: wake-up
data (inductive)
V2
125kHz
Inductive
Transmitter
V1
V3
Wake-up
pattern
detector
125kHz LF
Frontend
(3-dimensional)
V4
VDD1
VDD2
14V/24V
Vreg
C1
μC
μC
C2 +
Vreg
C4
Up to 2.5m
Downlink: data
(UHF)
UHF Receiver
V5
UHF Transmitter
V6
C3 +
Vbat
Component
Product
AVX Part number
V1, V2, V3, V4
Multilayer Varistor
MAV0010DP
V5, V6
Multilayer Varistor
VCAS04AG183R0YATWA
Specification
0603, 52Vac, 110 Pk-Pk @ 125kHz,
0.015J, 2A, 22pF Max
0402, 18Vdc, 3pF Max
VOLTAGE REGULATOR
78L05
OUT
1N914
IN
C3
+12/14V
14mA
GND
C1
Component
V1
122
Product
Multilayer Varistor
C2
V1
AVX Part number
VCAS080518C400DP
Specification
0805, 18Vdc, 0.3J, 120A, 550pF typ
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
BLUETOOTH
XTAL 13MHz
C4
V4
Power Control Chip
CLK-
CLK+
ANT
VDD1
Supply
Voltage
VCC
C1
V1
Speaker
SPK_IN
MIC
MIC_IN
V2
Component
V1
V2, V3
V4
V5
BlueTooth
CORE
C3
C2
Product
Multilayer Varistor
Multilayer Varistor
Multilayer Varistor
Multilayer Varistor
V3
AVX Part number
VCAS080518C400DP
VCAS060314A300DP
VCAS06AG183R0YAT3A
VCAS040218X400WP
KEYPAD
SWITCHES
I/O
I/O
V5
Specification
0805, 18Vdc, 0.3J, 120A, 550pF typ
0603, 14Vdc, 0.1J, 30A, 350pF typ
0603, 18Vdc, 3pF max
0402, 18Vdc, 0.05J, 20A, 65pF typ
123
TransGuard® Automotive Series
AVX Multilayer Transient Voltage Protection
Circuit Protection in Automotive Applications
LED DRIVER
+12V
OUT
IN
V1
0.1μF
V5
EN
SERIAL CLOCK
V2
V3
0.1μF
MAX 16806
SERIAL DATA
ILED
+5V REG
SCL
LEDs
SDA
CS+
SW
CS-
V5
RSENSE
D/M
Component
V1
V2
V3
124
Product
Multilayer Varistor
Multilayer Varistor
Multilayer Varistor
AVX Part number
VCAS120618E380
VCAS060318A400
VCAS06LC18X500
Specification
1206, 18Vdc, 0.5J, 200A, 930pF
0603, 18Vdc, 0.1J, 30A, 150pF
0603, 18Vdc, 0.05J, 30A, 50pF