Electronic Circuits in an Automotive Environment Herman Casier AMI Semiconductor Belgium...

Electronic Circuits in an

Automotive Environment

Herman Casier AMI Semiconductor Belgium [email protected]

2004 11 29 AID-EMC / HC / Electronic Circuits in an Automotive Environment slide: 2

Outline 1

Introduction Automotive Market and trends Characteristics of Electronics in a car Automotive Electronics Challenges

Cost and Time To Market

Quality and Safety Quality requirements Safety requirements DFMEA


Outline 2

High Voltage : the car battery History of the car battery Why switching over to 42V PowerNet Specifications of car-batteries Example: lamp-failure detector Example: high-side driver

High Temperature requirements Temperature range specification Functionality and reliability limits Diode leakage currents Example: bandgap circuit Example: SC-circuit


Outline 3

EMC general Definition of EMC Compliance and pre-compliance tests EMC standards EMC standards in IC-design

EME – Electro Magnetic Emission 1/150 test method EME what happens? EME how to cope with? Example: digital circuit current peaks Example: CANH differential output


Outline 4

EMS – Electro Magnetic Susceptibility DPI – Direct Power Injection method EMS compliance levels EMS what happens? EMS how to cope with? Example: rectification of single ended signal Example: rectification of differential signal Example: substrate currents in ESD diodes Types of substrate currents Example: jumper detection


Outline 5

Automotive transients (ISO-7637)(sometimes called Schaffner pulses)

Transient pulse definitions Transient pulses what happens? Example: supply & low-side driver Example: bandgap circuit

Acknowledgments

References


Trends in automotive

> 1920 + pneumatic systems low high technical skills + hydraulic systems low driving skills

> 1950 + electric systems increasing good technical skillsincreasing driving skills

> 1980 + electronic systems congestion low technical skills + optronic systems starts high driving skills

> 2010 + nanoelectronics congested very low technical skills + biotronic systems optimization decreasing driving skills

starts

> 2040 + robotics maximal and no technical skills + nanotechnology optimized no driving skills

CAR Technology TRAFFIC DRIVER SKILLS

> 1891 mechanical system very low very high technical skills


Automotive Electronics

Phase 1: Introduction of Electronics in non-critical applications

Driver information and entertainment e.g. radio,

Comfort and convenience e.g. electric windows, wiper/washer, seat heating, central locking, interior light control …

Low intelligence electronic systems

Minor communication between systems (pushbutton control)

No impact on engine performance

No impact on driving & driver skills



Phase 2: Electronics support critical applications Engine optimization:

e.g. efficiency improvement & pollution control Active and Passive Safety

e.g. ABS, ESP, airbags, tire pressure, Xenon lamps … Driver information and entertainment

e.g. radio-CD-GPS, parking radar, service warnings … Comfort, convenience and security:

e.g. airco, cruise control, keyless entry, transponders …

Increasingly complex and intelligent electronic systems

Communication between electronic systems within the car

Full control of engine performance

No control of driving & driver skills But reactive correction of driver errors.

Electronics impact remains within the car



Phase 3: Electronics control critical applications Full Engine control

e.g. start/stop cycles, hybrid vehicles … Active and Passive Safety

e.g. X by wire, anti-collision radar, dead-angle radar … Driver information and entertainment

e.g. traffic congestion warning, weather and road conditions … Comfort and convenience

Very intelligent and robust electronics

Communication between internal and external systemsInformation exchange with traffic network

Full control of engine performance

Control of driving and (decreasing) driving skills Proactive prevention of dangerous situations inside and around the car

Full control of car and immediate surroundings



Phase 4: Fully Automatic Driver (1st generation)

Traffic network takes control of the macro movements (upper layers) of the car

Automatic Driver executes control of the car and immediate surroundings (lower and physical layers)

ADAM : Automatic Driver for Auto-Mobile

or EVA : Elegant Vehicle Automat

Driver has become the Passenger for the complete

or at least for most of the journey

Driver might still be necessary if

ADAM becomes an Anarchistic Driver And Madman

or EVA becomes an Enraged Vehicle Anarchist


Automotive Drivers

Safety (FMEA) level 1: remains “in-spec” in Harsh environment

Increasing Complexity more functions and more intelligence : makes

the car system more transparant for the driver

Increasing Accuracy More, higher performance sensors : cheapest

sensors require most performance

Low cost and Time-To-Market (of course)

Legislation


Automotive IC’s

HBIMOS (2.0µm) I2T (0.7µm) I3T (0.35µm)


Technology Evolution

Feature size trend versus year of market introduction for mainstream CMOS and for 80-100V automotive technologies

2000 201019901980

0.1

1.0

10

Technology Node (µm)

BIMOS-7µm

SBIMOS-3µmHBIMOS-2µm

I2T-0.7µm

I3T-0.35µmCMOS

Year of Market Introduction


IntroductionTop automotive vehicle manufacturers (2000)

(top 14 manufacturers account for 87% of worldwide production)Source: Automotive News Datacenter - 2001


Introduction

Automotive electronic equipment revenue forecast

CAGR = 6.6% (2002–2006)

0

10

20

30

40

50

60

70

80

90

100

2003 2004 2005 2006

B$

Other Auto

Remote/Keyless Entry

Climate Control unit

Airbags

Dashboard Instr.

Auto Stereo

GPS

ABS

Engine Control units

0

5

10

15

20

25

2003 2004 2005 2006B

$

Automotive semiconductor consumption forecast

CAGR = 13.2% (2002–2006)Source : Dataquest December 2002


Introduction

Total semiconductor market (US$B)

0

50

100

150

200

250

300

2001 2002 2003 2004 2005 2006

Military/Aero (3%)CAGR=8% (2002-06)

Industrial (7%)CAGR=12% (2002-06)

Automotive (8%)CAGR=13% (2002-06)

Consumer (17%)CAGR=15% (2002-06)

Communications (24%)CAGR=14% (2002-06)

Data Processing (41%)CAGR=12% (2002-06)

Source : Dataquest November 2002


Introduction

Interior Light SystemAuto toll Payment

Rain sensor

Dashboard controller

Automated Cruise Control

Light failure control

Information Navigation

EntertainmentHead Up Display

Engine:

Injection control Injection monitor

Oil Level Sensing Air Flow

Headlight: Position control Power control Failure detection

Brake Pressure

Airbag Sensing &Control

Seat control: Position/Heating

Key transponderDoor module

Keyless entry

Central locking

Throttle controlValve Control

E-gas

Suspension control

LED brake light

Compass

Stability SensingPower Window Sensor

Backup Sensing

Gearbox: Position control

Where do we find electronics in a car


Introduction

Electronics are distributed all over the car-body

Distributed supply used for both power drivers and low power control systems

direct battery supply for the modules: high-voltage with large variation

Trend: Battery voltage from 12V 42V large supply transients due to interferences of

high-power users switching or error condition (load-dump)

Trend: comparable supply transients, lower load-dump transient


Introduction

Modules, distributed over the car-body have to comply with stringent EMC and ESD

low EME to other modules and external world low EMS (high EMI) for externally and internally

generated fields High ESD and system-ESD requirements

Trend: increasing EMC frequency and EMC field strength for the module.

Trend: increasing ESD voltages and power

Trend: more integration brings the module border closer to the chip border : the chip has to comply with higher EMC field strengths and ESD power.


Introduction

Modules on all locations in the car, close to controlled sensors and actuators

large temperature range: - 40 … +150°C ambient

Trend: increasing ambient temperature

Critical car-functions controlled by electronics Safety & reliability very important

Trend: increasing safety and reliability requirements

Communication speed and reliability

Trend: higher speed, lower/fixed latency, higher reliability and accident proof communications


Introduction

Many modules interface with cheap (large offset, low linearity) and low-power sensors

High accuracy and programmability of sensor interface: sensitivity, linearization, calibration … Trend: increasing sensor interface accuracy, speed and programmability with higher interference rejection and more intelligence

SOC-type semiconductors in module Lower cost mandates single chip

Trend: increasing intelligence requires state-of-the-art technology with high-voltage (80V), higher temperature (175°C ambient) and higher interference rejection (EMC, ESD) capabilities


AutomotiveIC design

AutomotiveIC design

Automotive Electronics Challenges

EMC & Automotive transients


Cost & TTMCost & TTM Quality & Safety

Quality & Safety

High Voltage High Temp.

High Voltage High Temp.


Cost & Time To Market

The automotive market is very cost driven : “Bill of Materials” and “Cost of Ownership” more important than component cost

Time To Market is quite long : start design to production is typically 2 … 3 yrs

but Time To Market is in fact “Time to OEM qualification slot” which is not flexible

Prestudy, design, redesign : typ 12 … 18 month Automotive IC qualification : typ 3 … 4 month OEM qualification : typ 6 … 12 month

The start of the OEM qualification is a very hard deadline


Outline

AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


Quality and Safety Required reliability ?

Most cars actually drive less than 10.000hrs over the cars lifespan of 10 … 15 years

Most electronics also only functioning during 10.000hrs but some are powered for > 10years

High reliability requirements : 1ppm for production reasons (low infant mortality) for safety reasons and long lifetime (failure rate).

Implications Design : 6 sigma approach Test: high test coverage (digital and analog),

test at different temperatures IDDQ, Vstress for early life-time failures

Packaging : high reliability


Quality and Safety

Safety requirements ? If a problem affects the performance, the

circuit/module functionality must remain safe (predictable behavior). Problems: circuit/system failure, EMC disturbance, car-crash (within limits) …

Non-vital functions may become inoperable until the problem disappears

Vital parts must remain functional

Implications Fault tolerant system set-up Worst Case Design including EMC disturbance DFMEA (Design Failure Mode and Effect Analysis)


DFMEA

What : Failure Mode and Effect Analysis is a disciplined analysis/method of identifying potential or known failure modes and providing follow-up and corrective actions before the first production run occurs. (D.H. Stamatis)

Why : avoid the natural tendency to underestimate what can go wrong

FMEA extends from subcircuit to component to system and assembly and to service, where each FMEA is an input for the next level.

Design FMEA (DFMEA) concerns the component design level.


DFMEA

FMEA does not include prototypes and samples because up to that point, modifications are part of the development. It is good practice though to include DFMEA already in the prestudy for its large implications on the final circuit

In the automotive industry, a standardized form and procedure has been published by AIAG

The header is not standardized and contains the design project references, the DFMEA version control, team and the authorization signatures.

The second part includes the mandatory items


DFMEA

Mandatory items for the DFMEA Functional block

Identification number Circuit part and Design function

e.g. input CLCK_in, Schmitt-trigger function

Actual state of the circuit (I) Potential failure mode

e.g. no hysteresis or hysteresis in one direction only Potential effect of failure

e.g. oscillation of clock signal [S] Severity of the failure: rank 1 … 10

e.g. 8 : critical failure: product inoperable


DFMEA

Mandatory items for the DFMEA (II) Actual state of the circuit (II)

Potential cause of failuree.g. Metal 1 crack

[O] likelihood of Occurrence of failure: rank 1 …10 e.g. 5 : medium number of failures likely

Preventive and Detection methods e.g. digital test of input does not include hysteresis

[D] likelihood of Detection of failure: rank 1 … 10e.g. 7 : low effectiveness of actual detection method

[RPN] Risk Priority Number: [RPN] = [O] x [S] x [D] e.g. 280 : high value : corrective action required


DFMEA

Mandatory items for the DFMEA (III) Corrective action

recommended corrective actione.g. include hysteresis test in test-program

Responsible Area or Person and Completion Datee.g. test engineer NN, wk 0324

Corrected state of the circuit Corrective action taken

e.g. testprogram version B1A [O] : Revised Occurrence rank e.g. 8 (unchanged) [S] : Revised Severity rank e.g. 5 (unchanged) [D] : Revised Detection rank

e.g. 1 : effect measured by standard test program [RPN] : Revised Risk Priority Number e.g. 40


DFMEA example


Outline

AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


High Voltage : the car-battery

Some History

~ 1955: 12 Volt battery introduced for cranking large & high compression V8 engines

1994: workshops in USA and Europe to define the architecture for a future automotive electrical system.

1995: study at MIT for the optimal system. the highest possible DC voltage is best.

1996: future nominal voltage = 42 Volt multiple of low-cost lead-acid battery below 60 Volt under all conditions (60V = shock-hazard protection limit for DC voltages)


The car-battery

March 24, 1997: Daimler-Benz presents the “Draft Specification of a Dual Voltage Vehicle electrical Power System 42V/14V”

is the de-facto standard since it is supported by the > 50 consortium members (http://www.mitconsortium.org)

The name:

42V = 3 X 12 V Lead-Acid Battery nominal operating voltage of a 12Volt battery is 14 Volt


The car-battery

Example of a dual voltage power system 14V/42V

The system can be equipped with two batteries or with one main battery (14V or 42V) and a smaller backup battery for safety applications …

M

Starter

G

Alternator

DC

DC

High Power 42 Volt loads

14 Volt loads

Battery 114 Volt

Battery 242Volt


The car-battery

Forecast of the 42V vehicle share in relation to the overall vehicle production in Europe


The car-battery

Why switching over to 42Volt battery ?

Electrical power consumption in a car rises beyond the capabilities of a 12Volt battery.

Limit for 14V generator power ~ 3kW Mean power consumption of a luxury car ~ 1.1kW

(corresponds to ~ 1,5l/100km fuel in urban traffic) The required power for all installed applications

in luxury cars already exceeds the generator capability.

New applications e.g. ISG (Integrated-Starter-Generator), X-by-wire, require much higher power


The car-battery


Alternator efficiency increases from 50% to 75% or more and creates smaller load-dump pulse (voltage supply pulse when the alternator runs at full power and the battery is disconnected)

New power hungry systems possible Electro mechanical or hydraulic brakes Electric water pumps “Stop-start system”: Integrates Starter and

Generator in a single unit (ISG). Electromechanical engine valve actuators ……


The car-battery


Most existing systems benefit from 42V Heating, ventilation and air conditioning Engine cooling (eliminates belts) Electromechanic gear shifting …..

Some systems still require 14V Incandescent ligtbulbs Low-power electronic modules Existing high-volume modules because of

redesign, qualification and production costs


The car-battery

Specification of the 42V battery

0-2

maximum dynamic overvoltage (load dump)

maximum continuous generator voltage including ripple

nominal voltage

minimum continuous operating voltage

minimum start voltage: 18V @ 15msec, 21V @ 500msecground

non-continuous battery reversal: -2V @ 100msec

18 21 30 50 58


The car-battery

Other specifications Battery reversal: no destruction

- non-continuous, small voltage for 42V - continuous, full battery voltage for 12V systems

Short drops: reset may occur 30V 16V / 100msec at 16V / 16V 30V

Slow increase/decrease: no unexpected behavior 48V 0V @ -3V/min. & 0V 48V @ +3V/min

Voltage drop test: reset behaves as expected 42V 30V 21V 30V 20.5V 30V 20V … and so on to … 30V 0.5V 30V 0V.

Electric modules see this car-battery voltage, which is further disturbed by conductive transients (ISO7637) and by ESD pulses.


The car-battery

Example specification of the current 12V battery

0

maximum dynamic overvoltage (load dump)

maximum continuous generator voltage

nominal voltage

minimum continuous operating voltage

minimum start voltage

ground

battery reversal

7 9 19 4014


The car-battery

Translation of the 42V battery specification into an 80V Technology requirement

0-2

+ 12V @ charge pumpfor high-side drivers ...

18 21 30 50 62

0-2 18 21 30 50 58

70 80

+ 10V margin for ESDclamping structures

fabrication margin


Example

Lamp-failuredetector

Directly connected to the car-battery

Sense inputs can be above or below VDDA

V(Rsense) detection Accuracy < 10mV

Output: low voltage CMOS levels

levelshift

Lamp OK

Vreg

Fuse OK

CMOSlogic

V

Vref

Lamp

Switch

Rsense

Fuse

Vbatt

VDDA

Vbg

LDO

levelshift

Vreg


Example

Lamp

Switch

Rsense

FuseVbatt

ESDprot.

Schaffnerprotection Comp.

Level shifter

Vgenerator

CMOSlogic


Example

Solution based on the low impedance of the source: the comparator and level shifter extract their supply from the sensor input.

ESD protection of the input with automotive-transient (Schaffner) resistant zener diodes (BVCES > 80V)

Protection for automotive transients (Schaffner) of all points connected to the car-battery by relative high value polysilicon resistors.

Resistors limit current during transient spikes Floating resistors can handle positive and negative spikes

Accuracy not impacted if IbxRpoly << 1mV

Adaptive V generator


Example

High-Side Driver for external NDMOS

D D DD

D D DD

D

D

Vcc

Vbatt

Ain

Aout

full swing inverter

DD

D D

DD

DD

D

OSC.

Vcc

Vbatt

OFFON

external

NDMOS

Cext

LOAD

charge pump with full swing invertor

ON / OFF level shifterswith slew rate control


Example

High-side driver for external NDMOS Simple Dixon charge pump

High voltage diodes Tank-voltage controlled by Vcc-regulator Uses a full-swing inverter (separate schematic) External tank capacitor

ON / OFF control logic Controlled charge and discharge current

controlled slew rate for minimum EME Bleeding resistors for low power and high temp.

Simplified schematic: no protection circuits except Vgs-zener for NDMOS no flyback & no important ground-shift between IC

and Load : NDMOS cannot go below substrate


Outline

AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


High Temperature

Temperature Range Specifications

Low temperatures : Environment e.g. Nordic countries, Alaska … Typical specification: - 50degC … - 40degC

High temperatures : Engine compartiment, brakes, lamps …

e.g. engine switch-off stops cooling and engine heat distributes. Engine restart however must work correctly

Typical specifications for Automotive ICs today : 125 … 150degC ambient with short peaks up to 170 … 200degC. (power devices go higher)

Requirements are increasing.


High Temperature Requirements

T4: Temperature extremes in accordance with SAE J1211 (5…10% of 7000…12000 hours lifetime)

Temperature zones and % of total operation time

in each temperature zone Mounting zone Module description

T1 (5%) T2 (20%) T3 (65%) T4 (10%)

Temperate zone, thermally isolated

- 40 °C 25 °C 60 °C 85 °C

Splash wall - 40 °C 25 °C 90 °C 140 °C

Attached to the engine or attached to the gearbox

- 40 °C 25 °C 95 °C 150 °C

Engine Compartiment

Throttle valve, close to the exhaust

- 40 °C 25 °C 120 °C 205 °C

Locations exposed to heat sources

- 40 °C 25 °C 90 °C 120 °C Chassis

Near breaks or hydraulics - 40 °C 25 °C 105 °C 175 °C

Dashboard, hat rack - 40 °C 25 °C 60 °C 110 °C Cabin Roof under strong sun

exposure - 40 °C 25 °C 90 °C 115 °C

Source: A.Blessing, AEC Workshop Nashville 2004


High temperature limitations

Functionality of on-chip components ? Bulk silicon can be used up to ~ 200 … 250degC.

(with appropriate design techniques) Below the intrinsic temperature of the lowest doped

regions (~200degC for 100V, ~250degC for 5V techno). The MOS transistor remains a transistor,

but with decreasing Vt and decreasing mobility increasing sub-threshold leakage increasing area

Diffusion and poly-resistors remain resistors Thin oxide capacitors remain capacitors Junction diodes remain diodes but the leakage

current goes up drastically. SOI can be used up to ~ 250 … 300degC GaAs can be used up to ~ 500degC



Reliability of components and package (most important limitations only)

Electromigration limits decrease use wider metals and more VIAs area increase of power devices.

Diffusion of silicon into aluminum using an Al/Si metallization extends the limit e.g. 1% Si – 99% Al alloy extends this to ~ 500degC.

Die attach not important below 200degC. use selected epoxies



Reliability of components and package (II) Wire bonding: the dominant failure mechanism

Chemical: inter-metallic growth and void-formation increases the bondpad/bondwire contact resistanceVery dependent on the type of plastic and the ionic contamination of the plastic.

Thermo-mechanical: delamination of bondpad and bondwire due to stress. Very dependent on the stress characteristics of plastic, the type of package and the size of chip.

Plastic encapsulation: depolymerization of the epoxy is closely linked to wire bond failure. New (green) packages are improved

Low stress (delamination) Low ion impurity and ion catching (voids)



Conclusions Reliability decreases according to the

Arrhenius-law reliability typically decreases by 2 for every 10degC

Wire bonding in a plastic package is the limiting factor for high temperature operationcurrent limit in production ~ 150degC for 10.000 hrs.

Diode leakage currents are the main limitations in circuit design.

Affect biasing and matching in low-power circuits Can give rise to latch-up

kTEAeRTR 0)(


Diode Leakage current

Leakage current mechanisms Moderate temperatures: Drift current ~ ni

leakage current dominated by thermal generation of electron-hole pairs in the depletion region

High temperatures : Diffusion current ~ ni2

leakage current dominated by minority carrier generation in the neutral region

In a single well technology is the PMOS leakage current (n-well to SP-drain) much lower than the NMOS leakage current (Epi to SN-drain)

Higher n-well doping less minority carriers n-well much thinner than epi less carriers Hole mobility lower than electron mobility

In a twin well is the difference much smaller


Diode Leakage current

Junction area 4 X 20mEpi doping: NA=10e15/cm3 Nwell doping: ND=4x10e16/cm3

(P. de Jong - JSSC-vol 33, dec 1998)

Nwell, 1.2 m CMOS technologyjunction areas shown in the figure

(I. Finvers - JSSC-vol 30, Feb 1995)


Example : bandgap circuit

NPN collector-substrate diode: bad N+/EPI diode, large area : leakage ~ 50 nA @ 150degC/unit. E.g. for n=8 & 3.5A/ NPN branch 10% error in current matching without extra transistor. 6.5% bandgap voltage rise.

PMOS mirror, Drain/Bulk diodes: good diode with small area and balanced leakage no mismatch

PMOS bulk/epi diode leakage subtracted from the PDMOS current source excess current.

NDMOS body/drain leakage in parallel with grounded current source. Drain/substrate leakage extracted from supply.

High voltage, low power bandgap

n : 1

n-1

VDD

VSS

VBG

DD

D


Example : SC circuit

Leakage currents: OpAmp inputs:

Gate Tunneling

Switches: Sub-threshold leakage Drain/Bulk junction

leakage Gate/Drain tunneling Impact Ionisation GIDL

Capacitor plate leakage

e.g. C2=2pF, 1nA leakage, 500V/sec CM droop

C2

C2

C1

C1

Switched Capacitor Circuit: the leakage sensitive points are the OpAmp input nodes in Hold mode.


Outline

AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


EMC : Definition

Definition (UK Defense Standard 59-41) “Electro Magnetic Compatibility is the ability of electrical and electronic equipments, subsystems and systems to share the electromagnetic spectrum and perform their desired functions without unacceptable degradation from or to the specified electromagnetic environment.”

In other words: The Electro Magnetic Emission (EME) must be low enough, not to disturb the environmentThe Electro Magnetic Susceptibility (EMS) must be low enough, not to be disturbed by the environment


EMC : Examples

EMS examples Unwanted but not safety critical

Car-radio, GPS … Safety-critical systems

require full in-spec functionality during EMC ABS system, airbag system, Motor control …

EME examples Unwanted EME sources

switching of heavy or inductive loads: lamps, start-motor, ignition …

fast switching circuits: digital circuits … Wanted EME sources

mobile phones, CB transmitters, radio stations … :


EMC : Compliance tests

Compliance tests have been standardized between the car-manufacturers, their suppliers and the government. Every car must pass these tests before it is allowed on the road

Examples:

Anechoic Chamber tests (600-700 V/m)

Environment tests (radio station)

……..


EMC : Pre-Compliance tests

The later EMC problems are detected, the more difficult the identification of the root-cause and the more limited and expensive the solution.

At final car qualification level, many modules could cause the EMC problem and there is no time for a redesign. The only solution is adding extra shielding and anti-interference components like chokes, coils, capacitors, which is very expensive.

At module qualification level, the PCB layout can be changed and extra components (chokes, coils, cap’s) can be added. This has less impact on the bill of materials but can impact the time to qualification slot.

It is mandatory to include EMC in all phases of the development : IC’s, PCB’s, modules and car-layout.

Pre-compliance tests have been standardized to enable this at module and at IC level.


EMC : Pre-Compliance tests

Pre-compliance tests agreed between car-manufacturer and module-supplier or between module-manufacturer and IC supplier. PRO: module and IC manufacturers make portable

designs CON: tendency to end up with a chain of

over-specification

Of the many EMC standards, 3 standards are particularly important for IC’s.

IEC 61967 for EME measurements (150kHz – 1GHz, narrow-band EME)

IEC 62132 for EMS measurements (150kHz – 1GHz, narrow-band EMS)

ISO 7637 for Automotive transients (EMS for power supply line disturbances)


EME standard: IEC 61967

IEC 61967 : Integrated circuits – Measurement of electromagnetic emissions 150kHz to 1GHz.

Part 1: General conditions and definitions

Radiated emission measurements Part 2: TEM-cell (Transversal Electromagnetic cell) Part 3: Surface scan method

Conducted emission measurements Part 4: 1 Ohm/150 Ohm method Part 5: Workbench Faraday Cage method (WBFC) Part 6: Magnetic probe method


EMS standard: IEC 62132

IEC 62132 : Integrated circuits – Measurement of electromagnetic immunity 150kHz to 1GHz.

Part 1: General conditions and definitions

Radiated immunity measurements Part 2: TEM-cell (Transversal Electromagnetic cell)

Conducted immunity measurements Part 3: Bulk current Injection method (BCI) Part 4: Direct RF Power Injection method (DPI) Part 5: Workbench Faraday Cage method (WBFC)


Transients standard: ISO 7637

ISO 7637 : Road vehicles – Electrical disturbance by conduction and coupling

Part 0: General and Definitions Part 1: Passenger cars and light commercial

vehicles with nominal 12 V supply voltage – Electrical transient conduction along supply lines only

Part 2: Commercial vehicles with nominal 24 V supply voltage – Electrical transient conduction along supply lines only

Part 3: Passenger cars and light commercial vehicles with nominal 12 V supply voltage and Commercial vehicles with nominal 24 V supply voltage – Electrical transient transmission by capacitive and inductive coupling via lines other than the supply lines.


EMC standards in design

How to include EMC in the IC development flow EMC deals with electromagnetic fields. EM noise generator emits EM-energy, wanted or

unwanted. EM noise receiver susceptible to this EM-energy The coupling channel conducts EM-energy from

the noise-generator to the noise-receiver via radiation or conduction.

EM-noise generator

EM-noise generator

EM-noise receiver

EM-noise receiver

radiation

conduction



EM-fields are not compatible with the SPICE based simulation environment of IC-design, which is “electrical only”.

At the IC level, EM-fields can be modeled by Electrical fields only since the dimensions on the chip and in the package are much smaller than the wave length of the EMC signals

e.g. in air : λ = 30 cm @ 1GHz >> chip dimensions On-chip current loops are very inefficient

antennas for electromagnetic emission and susceptibility. (“rule of thumb”, L < λ / 20).

The variations are quasi-stationary and a Low-Frequency modeling with L, R and C is adequate.



Radiated emission and susceptibility is not the major problem for IC’s.

Conducted emission and susceptibility to the efficient antennas on the PCB and the cable harness is the important problem.

Two EMC conductive methods, compatible with simulation, have been standardized.

IEC 61967-4 (1 / 150 method) IEC 62132-4 (DPI – Direct Power Injection) Note that ISO 7637 (Schaffner) is compatible

These methods model conducted EMC between IC and PCB, not the EM-field. Generated EM-fields are function of module and wiring layouts.

Limit setting for these methods is based on the accumulated experience of the chip and module manufacturers



System level test Radiated

susceptibility TEM cell tests

ISO11452 –3 Shielded chamber

tests ISO11452 –2

Conducted susceptibility

ISO 7637–1

Conducted and radiated emission CISPR25

Etc…

IC level tests : empirical validation and theoretical analysis

Susceptibility Like IEC 62132-4

(Direct Power Injection)

Like ISO 7637-1 (Conductive transient pulses)

Emission Like IEC 61967-4

(1 Ohm/150 Ohm method)


Outline

AutomotiveIC design

AutomotiveIC design

EME & EMS & Automotive

transients


transients


Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


EME 1 / 150 test

RF

cu

rre

nt

1

4950

51

12050

6.8nF

51

11050

6.8nF30

30Spectrum analyser

Spectrum analyser

Spectrum analyser

impedance matching network for Line Driver

impedance matching network for CANH-bus

150trace

150trace

150trace

PowerSupply

LineDriver

CANH

CANL

VDD VSS

DUTp

rob

e


EME 1 / 150 test

1 method measures the RF sum current in a single ground pin (RF current probe). This measures the RF return current from the various current loops (emitting antennas) of the PCB.

150 method measures the RF voltage at a single or at multiple output pins, which are connected to long PCB traces or wiring harness. (150 is the characteristic impedance of wiring harnesses in a vehicle). Various measurement configurations are used for different types of outputs.


Standard EM-field graph

0

6

12

18

24

30

36

42

48

54

60

66

72

78

84

105 2 3 4 5 6 8 106 2 3 4 5 6 8 107 2 3 4 5 6 8 108 2 3 4 5 6 8 109 Hz

A

B

C

D

E

F

G

H

I

K

L

M

N

O

12

3

4

5

6

7

8

9

10

11

1213

14

1516

17

18

19

ab

cd

ef

gh

ik

lm

no

pq

rs

tu

vw

yz

f

dBV

V emission limitexample: H-12-n-O


EME what happens

EME is generated by HF currents in external loops, which act as antennas.

Sources of the HF currents Switching of core digital logic: glue logic, core, DSP,

memory, clock drivers … synchronous logic generates large and sharp current peaks with large HF content

Activity of the analog core circuit does not generate large current peaks

Switching of the digital I/O pins fast and large current peaks directly to the PCB

High power output drivers large current peaks to the PCB and wiring harness.


EME how to cope with

Internal measures Limit the switching power to the external

Use low power circuits & circuit techniques - low power flip-flop, memory … - architecture with different clock domains - lower or adaptive supply voltage - …. Note: gated clocks are not efficient for EME if modes exist where all gates are open.

Use a more advanced technology Use on-chip capacitors

EME (HF) looks at switching power spectrum, low-power digital looks at mean dissipated power.



Shape the current peaks to the external Slow down the switching edges

- MS-FF and 2phase clock - asynchronous logic - controlled edges for I/O or power driver - ….

External and Chip-layout measures Differential output signals e.g. CAN, LVDS …

twisted-pair like lines generate less EME and are less susceptible to EME

VDD and VSS close to each other - differential signals (see above) - external decoupling easier and more efficient



EME of the module is the result of the current peaks generated by the IC times the efficiency of the emitting antennas of the PCB and wiring harness.

The current peaks simulated or measured with the 1 / 150 method do not predict the correct value of the emission but give a good relative indication. A correlation with the actual measured EME of the module is required.

Each manufacturer specifies his own limits for the emission as simulated or measured by the IEC 61967-4 1 / 150 method.


Example

In the example, spectra of different current pulses are evaluated. The current pulses are simplified.

Simulated spectra Reference current pulse in existing technology.

100mA outgoing pulse 100mV in 1 probe Distributed pulse: amp. / 2, freq. x 2

HF spectrum remains, LF spectrum changes Pulse with slower edges & same power: amp. / 2

HF spectrum lower, LF spectrum remains Same logic in newer technology (2 generations):

power / 2, amp. X 1, width / 2, slopes x 2 HF spectrum higher, LF spectrum lower

pulse widthWpulse

pulse slope80% Wpulse

pulse top20% Wpulse


ExampleSpectrum of different pulses

refe

ren

ce s

pec

tru

m

(1

00m

V,

5.0

nse

c,

1M

Hz)

[

E -

4 -

c ]

d

istr

ibu

ted

pu

lse

(

50m

V,

5.0

nse

c,

2M

Hz)

[

E -

4 -

c ]

sl

ow

er p

uls

e sl

op

es

( 5

0mV

, 10

.0n

sec,

1

MH

z)

[ E

- 5

- e

]

new

tec

hn

olo

gy

(

100m

V,

2.5

nse

c,

1M

Hz)

[

F -

4 -

b ]

0

6

12

18

24

30

36

42

48

54

60

66

72

78

84

105 2 3 4 5 6 8 106 2 3 4 5 6 8 107 2 3 4 5 6 8 108 2 3 4 5 6 8 109 Hz

A

B

C

D

E

F

G

H

I

K

L

M

N

O

12

3

4

5

6

7

8

9

10

11

1213

14

1516

17

18

19

ab

cd

ef

gh

ik

lm

no

pq

rs

tu

vw

yz

f

dBV

V

reference spectrum& distributed pulse

slower pulse slopes

new

tech

nolo

gy


Example

CANH differential and single ended output (for the given pulse mismatch)

Frequency / Hertz

0

6

12

18

24

30

36

42

48

54

60

66

72

78

84

105 2 3 4 5 6 8 106 2 3 4 5 6 8 107 2 3 4 5 6 8 108 2 3 4 5 6 8 109 Hz

A

B

C

D

E

F

G

H

I

K

L

M

N

O

12

3

4

5

6

7

8

9

10

11

1213

14

1516

17

1819

ab

cd

ef

gh

ik

lm

no

pq

rs

tu

vw

yz

f

dBV

V

CANH – single ended output [ 5 - h ]CANH – differential output [ F – 7 – h ]

CANH bus with

termination

150 method

6.8nF110

51 50

60

60 60

60

CAN driver

2.5V

CANHA=1.855Vperiod=4uwidth=2utr= 55.3ntf= 55.3n

CANLA=1.845Vperiod=4uwidth=2utr= 53.2ntf= 55n

110


Outline

AutomotiveIC design

AutomotiveIC design


transients


transients


Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


EMS DPI test

Measurement set-up

The measurement set-up uses a power source

For Zin(DUT) > 200, the power source can be replaced by a voltage source.

For Zin(DUT) < 50, the power source is better replaced by a current source (Norton equivalent)

Note that Zin(DUT) is frequency and signal dependent

50

directional coupler

50

DUTRF power source

PreflPfwd

C co

up

le

R pro

t50


EMS DPI test

Simulation models

Simulation model for Zin > 200

Guideline for amplitude AV

AV = 22V @ 5W DPI (level 1)

AV = 7V @ 0.5W DPI (level 2)

AV = 2.2V @ 50mW DPI (level 3)

Simulation model for Zin < 50 Guideline for amplitude AI

Pinj : required immunity level

Zin50Zin50

PA injI

DUTCcouple

50 Zin < 200

Ccouple Rprot DUT

Zin > 200RF voltage sourceV = AV · sin(·t)

RF current sourceI = AI · sin(·t)

50


EMS compliance levels

Not all I/O pins of the IC are connected to the wiring harness and unprotected.

Level 1: direct connection to the environment Level 2: direct connection to the environment but

some external low-pass filtering is available. e.g. signal conditioning input stages, direct sensor interfaces …

Level 3: No direct connection of the I/O to the environment. e.g. interface chips connected to sensor chips in the same module, A/D converter input stages …


EMS compliance levels

EMS caused malfunction is not always detrimental Class A: all functions of a device/system perform

within the specification limits during and after the exposure to the disturbance.

Class B: some functions can go temporarily beyond the specification limits during the exposure. The system recovers automatically after the exposure.

Class C: some functions can go temporarily beyond the specification limits during the exposure. The system does not recover automatically but requires operator intervention or system reset.

Class D: degradation or loss of function, which is not self-recoverable due to damage of the IC or loss of data.


EMS what happens

The incident high-frequency electro-magneticpower is partially absorbed in the IC and causes disturbances in different ways:

1) Large HF voltages into a high-impedance node

2) Large HF currents into a low-impedance node

3) Large HF power into a node, which switches from high-impedance to low-impedance at device limits, at protection voltages or at frequency breakpoints.

Rectification/pumping, Parasitic devices/currents and Power dissipation are the three important disturbing effects of EMS


EMS what happens

1) Large HF voltages into a high-impedance node Medium power dissipation e.g. 9% of DPI for 1k Linear large signal behavior of components and

structures in the signal path no effect Non-linear behavior of components and structures in

the signal path rectification effects (pumping) on capacitors in the signal path. : important disturbance on a chip e.g. bias pumping

Capacitive coupling input devices into the substratee.g. large driver in the OFF state, ESD structures substrate currents and substrate bounce : important effect for latch-up, pumping …

Capacitive coupling to adjacent devices or structures e.g. Cm = 100fF gives | Zm | = 10 k at 159MHz


EMS what happens

2) Large HF currents into a low-impedance node Large power dissipation e.g. 83% of DPI for 10 :

Important effect on chip. Linear large current behavior of components and

structures in the current path no effect Non-linear large current behavior of components and

structures in the current path rectification effects (pumping) in the signal path: important disturbing effect on a chip.

Inductive coupling to adjacent devices or structures : only important for bondwires and leadframe e.g. 100mA @ 159MHz gives ~ 750mV in an adjacent, open wire.


EMS what happens

3) Large HF power into a node, which switches from high-impedance to low-impedance e.g. at device limits or at protection voltages or at frequency breakpoints

Combines high voltage and large currents Large power dissipation in clipping devices or

protection structures Important effect clipping activates parasitic devices & current paths

large current peaks in the supply lines or other pins generates EME in other loops on the PCB. large current peaks in the substrate through parasitic devices important effect e.g. latch-up, substrate coupling …

Nature of the signal path can change with frequency important effect, difficult to cope with.


EMS how to cope with

Guidelines Use good large signal and HF models Include all parasitic components of the devices

(internal and external) Design, simulate and layout with all parasitics

Avoid rectification : make circuits symmetrical Differential circuit topologies and layout Limit voltage input range of sensitive devices

such that they do not go in non-linear behavior or in degradation conditions.

Limit frequency input range of sensitive devices : band-limited signals


EMS how to cope with

Make circuits robust for rectification Design for high CMRR & PSRR Keep internal node impedances low Keep sensitive nodes on-chip

Avoid / control parasitic devices and currents Use protection devices that clip beyond the

required EMS injection levels Make protection levels symmetrical

with respect to the signal Minimize substrate currents Collect substrate currents in controlled points


ExampleRectification

LF: both the NMOS/OpAmp circuit and the LP-filter follow the input variations Iout is correct

MF: the NMOS/OpAmp circuit follows Vin and conducts a linear current in the PMOS diode. VgsPMOS(Id) is non-linear and the LP-Filter output voltage is the mean of the rectified VgsPMOS (pumping) Iout decreases

HF: the NMOS/OpAmp becomes a Source follower which rectifies the input current, The rectified current is largely linearized in the PMOS diode before the LP-filter. Iout returns to correct value

Vref

Rext DPIsource

IoutLP-filter

ESD

CHIP

LF: below LP-filter & OpAmp GBWMF: between LP-filter & OpAmp GBWHF: above LP-filter & OpAmp GBW

Note: at high DPI voltages, the ESD and NMOS diodes can also rectify the current (below OpAmp GBW)


Example

Current source error (filtered) as function of the DPI source voltage and frequency

100k 1M 10M

99%

90%

0%

50%

80%

95%

98%

frequency Vin

(Hz)

Iout (% of Iout without DPI source)

0.5 Vin

1.0 Vin

1.5 Vin

2.0 Vin

3.0 Vin

Vin: DPI source voltage (arbitrary units)

20 30 40 50 60 7040

50

60

70

80

90

100

Time/µsec

Iout (%)

Vin : 500kHz – 1.0*Aref

Vin : 500kHz – 1.5*Aref

Effect of rectification on the output current (pumping)


Example

Rectification in a differential comparator

DPISource

input signalVout

Comparator

DPISource

input signalVout

Comparator

Emitter follower rectification due to large Ccs of current source replace current source by resistor


Example

Further EMS improvement

DPISource

input signal AttenuatorVout

Comparator

DPISource

input signal Filter Vout

Comparator

Input Attenuator large improvement (LF & HF) also for LF & HF signals beyond the supply voltages reduced sensitivity

Input Filter large improvement (only HF) also for HF signals beyond the supply voltages no sensitivity reduction


Example

Effect of the EMS improvements

100

10

1

1M 10M 100M 1G

EMI

DPI source strength (relative units)

frequency

(Hz)

1

2

3

5

4

(1) original circuit with current source

(2) current source replaced by resistor

(3) with input attenuator

(4) with input filter

(5) with input attenuator and input filter

The EMI value in the graph is the maximum value of the DPI source strength for which the comparator gain > 2


Example

Parasitic currents & substrate currents

VDD

VSS

INPUT

Isub1to Substrate

Isub2from other N-tubs

Lateral NPN

Vertical & Lateral PNPN-buried layer

N-tub N-wellP+N+P+

P-epi

P-substrate

N-buried layerN-tubN-well

P+N+P+

P-epi

P-substrate

P-wellN+N+

Example: substrate currents in an ESD protection structure


Types of Substrate Current

Three important types of substrate current Substrate currents, injected into the substrate by a PNP

transistor where the substrate is the collector, by diode breakdown, by impact ionization … Effect: substrate biasing, which can activate other parasitic transistors or cause latch-up.

Substrate currents, extracted from the substrate by a forward biased diode. This diode becomes a lateral NPN with any other neighboring N-region as collector. Effect: extraction of currents from other distant N-regions (up to millimeters distance).

Capacitive currents due to junction or oxide capacitors, coupled to the substrate. Effect: substrate biasing (bounce) & capacitive coupling to other junctions or oxide capacitors


Example

Problem: for the input strapped to ground, the output toggles from low to high for low EM injection

Cause: substrate current extraction from the NMOS drain during negative pulses overrides the bias current

Vin

Vclamp(1.5·Vbe)

Vcc

Vbat

Vbias

Vout

ESD zener diode

ESD protectionfor full battery

voltageSchmitt trigger

regulator

large current pull-upIsub

Isub

Isub

Ibias

DPI Source


Example

Solution: new ESD protection circuit without substrate NPN, back-to-back zener diodes and shielding of the NMOS gate.

Vin

Vcc

Vbat

Vbias

Vout

back-to-back ESD zener diodes

ESD protectionfor positive and

negative battery voltages

Schmitt triggerwith shielded

NMOS-gate

regulator

large current pull-upIsub

DPI Source

LP-filter


Outline

AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.


Automotive transients

Standard test pulse 2

Interruption of the current in an inductor in series with the device under test

(ISO 7637, part1)


Disconnection of a supply from an inductive load, while the device under test remains in parallel with the inductive load

(ISO 7637, part1)



Standard test pulses 3a and 3b

These pulses simulate transient, occurring as a result of switching processes. They are influenced by distributed capacitances and inductance of the wiring harness.

(ISO 7637, part1)




LOAD DUMP: This happens when the battery is disconnected while it is being charged by the alternator.

(ISO 7637, part1)


BATTERY VOLTAGE DROP: During motor start, the battery is overloaded and the voltage drops, especially in cold weather.

(ISO 7637, part1)



For alternators with autoprotection

Standard test pulses 5 : LOAD DUMP clamped

Load dump amplitude depends on alternator speed and field excitation. Load dump duration depends on the time constant of the field excitation circuit and the amplitude.

Today most alternators have an internal protection against load dump surge. The 6 zener diodes clamp above 24Volt.



.


Simulates the decrease of the magnetic field of the alternator when the engine stops.

(ISO 7637, part1)


This disturbance occurs when the ignition current is interrupted.

(ISO 7637, part1)


Test pulses

(ISO 7637, part1)

Test levels

(values agreed to between car manufacturer

and supplier)

Pulse type

Series resistance

Impulse duration

I II II IV

1 10 2 ms -25V -50V -75V -100V

2 10 50 s +25V +25V +75V +100V

3a

3b

50 0.1 s -40V

+25V

-75V

+50V

-110V

+75V

-150V

+100V

4

10 up to 20 sec

9V

(12V -3V)

7V

(12V-5V)

6V

(12V-6V)

5V

(12V-7V)

5 1

up to

400ms +35V +50V +80V +120V

aaaaaaaaaaaaaaaaaaaa


The customer has to define the “Level of Test” according the needs of his application.

Typical requirement today: Level IV, except Load dump: Level II - III.


Transients – What happens

Automotive transients (ISO-7637-1): electrical transient conduction along the supply lines only. other IC pins indirectly connected to supply via load devices (outputs) or sensors (inputs)

ISO-7637-1 describes two types of pulses Pulse 4 defines the minimum battery voltage.

Note: battery voltage = module supply voltage. Internal IC supply voltage = module supply – reverse battery diode – module supply regulator – internal supply regulator of the chip.

Pulses 1, 2, 3a, 3b, 5, 6 and 7 describe high voltage, high power transient disturbances on the supply line.


Transients – what happens

The high voltage, very high power transient disturbances can cause excessive substrate currents and power dissipation in the IC if they exceed the voltage capability of the chip.

The IC can only survive if: Transient peak voltages blocked

e.g. high-voltage techno or lower level transient spec Transient voltages externally limited

e.g. static with zener diodes (clamped load dump) e.g. dynamic limitation with RC (all other pulses)e.g. reverse battery protection diode

Peak currents internally or externally limited e.g. series impedance of load or sensor or external R e.g. low impedance output dynamically switched-off


Automotive transients – example

Typical input supply protection reverse bias diode RC-filter (pulses 1, 2, 3a, 3b)

Low-side NDMOS driver with ± 100V input range NDMOS with reverse voltage diode (PNP) NDMOS drive logic with slope control Clamp circuit to prevent lateral NPN activation during fast negative pulses below ground

D

Vbatt Vbat_filtered

Vcc

bandgap

regulator

Low-side Driver+/- 100V input range

NDMOS driver with negativevoltage diode

dynamic Schaffner

clampcontrol logic

(slope control)

clamp to preventsubstrate current

extraction

ONOFF

VccVbat_filtered


Automotive transients – example

Bandgap with improved tolerance for substrate currents and temperature

Transient or EMC induced substrate current extraction and high temperature leakage currents from all N/Sub diodes. (NPN collectors, PMOS N-well, NMOS S/D diffusions)

Transient or EMC induced current injection into the substrate, connected to AGND.

Capacitive coupling through all N/Sub diode capacitors

No direct effect on the most sensitive bandgap circuits: bipolar PTAT and OpAmp input stage.

Vbg

Vbatt

AGND

n : 1


AutomotiveIC design

AutomotiveIC design




Quality & Safety

High Voltage

High Temp.

High Voltage

High Temp.

Fully compliant AutomotiveIC design

Fully compliant AutomotiveIC design

ResultResult


Result

Combination of Silicon and Design Technology

for Automotive Applications


Ackowledgments

This work would not have been possible without the cooperation and dedication of many colleagues at AMI Semiconductor.

I would like to thank in particular: Michel De Mey, Aarnout Wieers, Geert Vandensande, Hans Gugg-Schweiger, Eddy Blansaer, Luc Dhaeze, Koen Geirnaert, Herve Branquart and many others.


References – 1

P. Thoma, “Risks for the automotive industry with regard to the market shift in world-wide semiconductor demand (in German)”, VDI Berichte nr. 1287, pp 1-12, 12 September 1996.

“Potential Failure Mode and Effect analysis (FMEA)”, 3th edition, April 2001, Chrysler Corporation, ford Motor Company, General Motors Corporation.

IEC 61967-4, “Integrated Circuits – Measurement of Electromagnetic Emissions – 150 kHz to 1 GHz, Part 4: Measurement of Conducted Emission, 1Ohm/150Ohm Method”.

IEC 62132-4, “Integrated Circuits – Measurement of Electromagnetic Immunity – 150 kHz to 1 GHz, Part 4: Direct RF Power Injection Method”.

ISO 7637-1 , ISO 7637-2, Road Vehicles – Electrical Disturbance by Conduction and Coupling, vehicles with nominal 12V (part 1) and 24V (part 2) supply voltages – Electrical transient conduction along supply lines only.

J. Kassakian, “Challenges of the New 42Volt Architecture and Progress on its International Acceptance”, VDI Berichte nr. 1415, pp. 21-35, 08 October 1998

Hans-Dieter Hartmann, “Standardisation of the 42V PowerNet - History, Current Status, Future Action”, HDT conference "42V-PowerNet: The first Solutions", Villach, Austria, September 28-29, 1999


References - 2

K. Ehlers, “The effect of the 3-litre car on the architecture of the automotive electrical system“, 5.98, http://www.sci-worx.com → Partner → Forum Bordnetzarchitektur

Ivars G. Finvers, J. W. Haslett, F.N. Trofimenkoff, “A High Temperature Precision Amplifier”, IEEE Journal of Solid-state Circuits, vol. 30, pp 120-128, February 1995.

Paul C. de Jong, “Smart Sensor systems for High-Temperature Applications”, PhD dissertation, T.U. Delft, the Netherlands, November 1998.

Paul C. de Jong, Gerard C. M. Meijer, Arthur H. M. van Roermond, “A 300°C Dynamic-Feedback Instrumentation Amplifier”, IEEE Journal of Solid-State Circuits, vol. 33, pp. 1999-2009, December 1998.

“High Temperature Electronics”, edited by F.Patrick McCluskey, Richard Grzybowski, Thomas Podlesak, CRC Press, Boca Raton, Florida, 1997, ISBN 0-8493-9623-9

W. Wondrak, A. Dehbi, G. Umbach, A. Blessing, R. Getto, F. P. Pesl and W. Unger, “Passive Components for High Temperatures: Application Potential and Technological Challenges” AEC Reliability Workshop, Nashville 2004

Ron Schmitt, “Understanding Electromagnetic Fields and Antenna Radiation takes (almost) no Math”, EDN magazine, March 2, 2000, pp 77-88.


References - 3

Wolfgang Horn, Heinz Zitta, “A Robust Smart Power Bandgap Reference Circuit for Use in an Automotive Environment”, IEEE Journal of Solid-state Circuits, vol. 37, pp 949-952, July 2002.

M. De Mey, “Robustness in Analog Design”, Proceedings of the 12th Workshop on the Advances in Analogue Circuit Design, AACD 2003, 15-17 April 2003, Graz Austria

B. Deutschmann, “Improvement of System Robustness through EMC Optimization”, Proceedings of the 12th Workshop on the Advances in Analogue Circuit Design, AACD 2003, 15-17 April 2003, Graz Austria

D. Temmen, “Noise rejection of clocked interference sources (in German)”, VDI Berichte nr. 1646, pp. 599-618, 27 September 2001

Robert J. Widlar, “Controlling Substrate Currents in Junction-Isolated IC’s”, IEEE Journal of Solid-state Circuits, vol. 26, pp 1090-1097, August 1991.

Bruno Murari, “Power Integrated Circuits, Problems, Tradeoffs and Solutions”, IEEE Journal of solid-state Circuits, vol 13, pp 307-319, June 1978

Electronic Circuits in an Automotive Environment Herman Casier AMI Semiconductor Belgium...

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