Wireless Power Consortium

Seoul - WPC 1505

Wireless Charging in Car Infotainment

November,12th 2015

Max Cortiana

Product Marketing Manager

STWBC

Introduction 2

• Convergence of cars and smartphones is becoming a reality

• Integration improves the end-user experience with benefits for safety,

performances and convenience

• Wireless charging in car infotainment challenges specific constraints

• ST and Qi meet the requirements and make it happen

Why

ST and QiWireless

charging

in the car

Improved

end-user

experience

Safety

security

performance

STWBC

0

500

1000

1500

2000

2009 2010 2011 2012 2013 2014

Mo

bil

e p

ho

ne s

ale

s i

n m

illi

on

un

its

0

20

40

60

80

100

1990 to 1999 2000 to 2011 2012 2013 2014 2015

Car

sa

les

in

mil

lio

n u

nit

sCars and mobile phones

Phone and Drive3

Integration between automotive and mobile is happening

let’s have a look on how…

STWBC

Step 1 of integrationPhone and Drive

4

Use mobile phone AND drive

Easy, not very effective, and of course raises safety concerns

STWBC

Step 2 of integrationHands-free – Voice integration

5

Use mobile phone features AND drive

Requires some kind of interaction with the phone (address book, texting, GPS)

Mobile phones are still considered an accessory

Positioning: no integrated and convenient spaceVoice and music

Power: cigarette lighter or USB port still require an inconvenient cable and

connectors

STWBC

Next step Infotainment integration: data, voice, power

6

Just drop your phone and go!

• Qi provides a seamless way to

drop and charge the phone

• Car makers can fully integrate the

mobile phone into the car body

Use personalized phone Apps AND drive

Mobile phone is a complementary part of the car

Seamless power is required – Wireless charging requires well defined, in-car positioning

STWBC

X, Y Free Positioning 7

• On a smartphone the internal

position of the receiver coil is not

known by user

• Multi-coil topologies are preferred

for automotive, giving a better

performance

Compared to residential wireless power charger, free positioning of the portable device

is more important in a vehicle

Active area for

single-coil system

Active area for

multi-coil system

STWBC

Safety 8

• WPC Qi low power includes this

requirement in the standard

• Overheating prevention is ensured

• Safety: a portable device can become a

projectile in case of crash

• Mechanical tools for holding the device

should be provided

Foreign-object detection ensures that inductive charging stops if metallic objects are

inserted (e.g. keys, coins)

STWBC

Key Fob & Smart-Key interference 9

• Remote Keyless operates typically at

315 MHz or 433 MHz + 125 kHz if

proximity detector feature is added

• Guidelines need to be followed and

specific tests need to be performed

Without proper transmitter design (with lowest EMI radiation),

electronic key could be disturbed, influenced by key fob and charger proximity

In case of interference, key is not detected and car engine will not start

STWBC

Radiated Emissions 10

Several standards: CISPR-25, 2004/104/EC, SAE J1113/41

CISPR-25 Limits - Tests performed in anechoic room

Level 5

Level 1

433MHz ISM band

315MHz ISM band

FM band

AM band

CISPR25:

• Several limits/ levels

can be defined

• Level 5 is the most

stringent

• Horizontal/ vertical

polarization must be

tested

• Average/ quasi-peak/

peak limits must be

filled

STWBC

Conducted Emissions 11

Several standards: CISPR-25, SAE J1113/41

CISPR-25 Limits

Level 5

Level 1

AM band

FM band

CISPR25:

• Several limits/ levels

can be defined

• Level 5 is the most

stringent

STWBC

Main surges in automotive 12

• Reverse vehicle battery connection

• Transients due to supply disconnection

from inductive loads

• Transient from sudden interruption of

current in a device connected in

parallel with the wireless charger

• Transients due to switching processes

• 24 V jump start

• 6 V crank

Wireless charger equipment connected to battery vehicle

Several standards depending on regions describe the surges that should be respected:

ISO7637-2, SAE J1113/41, ISO16750, SAE J2139, JASO D001-94

Nominal

14V

Pulse 4

6 V Crank

Tests A (79 V to 101 V)

and B (35 V)

Load DumpPulse 3a & 3b

+ 150 V220 V /

Spikes

24 V Jump Start

Reverse Battery

0V

Pulse 2

+ 112 V

Pulse 1

150 V

+12 V battery

Power rail-conducted aggressions

+24 V battery

STWBC

Component packaging test

+/- 25 kV (category 3)

Air discharge

+/- 15 kV (category 3)

Contact discharge

Electrostatic discharge (ESD) 13

All areas that can be reached

by person using the vehicle:

• Switches

• Displays

• Surfaces

• Antennas

Electrostatic discharge (ESD) several standards:

ISO7637-3, SAE J1113/41, IEC61000-4-2, ISO10605

Data-line conducted aggressions

330 pF

ESD generator discharge circuits

ISO10605

+/ -8 kVContact

+/ - 15 kV

Air

150 pF

ESD generator discharge circuitIEC61000 -4-2

Pulse 3a & 3b

Spikes

0 V

+80 V -80V /

150 pF

330 Ω

From inside vehicle

+/- 15 kV (category 3)

Air discharge

+/- 8 kV (category 3)

Contact discharge

From outside vehicle

+/- 25 kV (category 3)

Air discharge

+/- 8 kV (category 3)

Contact discharge

Worst cases

(link to coupling mode

and level system (12 V

to 42 V))

0 V 0 V

330 Ω 330 Ω

STWBC

Idle Current 14

• Lowest standby and best efficiency in use

will improve vehicle autonomy

• Lowest leakage current required for parts

directly connected to battery (typically much

below 100 µA)

• Lowest standby current to maximize time

before car goes to sleep mode (today’s

solutions goes from 20 to 200 mW)

For traditional engine vehicles, greater electrical power consumption means reduced

fuel economy

For an electric vehicle, it means reduced autonomy

STWBC

NFC & Qi : Coexistence 15

NFC detection area should be bigger than Qi

active area, typical use cases:

• Pair a smartphone by tapping it against a tag,

• Turn on your bluetooth on your smartphone

• Activation of personal presets: radio station,

seat positions, mirror settings

Near Field Communication (NFC) and WBC should be able to operate simultaneously

NFCantenna

Qi

Coil

NFC active area

Qi active area

STWBC

NFC & Qi : Coexistence 16

• NFC protocol is quicker than Qi protocol

• NFC communication should be initiated at larger

distance before WBC perform digital ping

Special care must be taken on the NFC side:

• NFC coil and Qi inductors are tightly coupled

• Qi generates an intense magnetic field at close

proximity that can damage the NFC Tag or

Transceiver

• Specific protections and filtering are needed

For the best user experience, when the phone is dropped onto the console

it must be detected immediately by the application

WBC + NFC

NFC Radiation pattern

Qi Radiation pattern

STWBC

Takeaways 17

• Qi-certified solutions with foreign-object detection

• Multi-coil transmitters for a bigger active area

• Good surge / ESD protections

• Good EMI / EMC design

• NFC coexistence

• Extra-low leakage current and standby current

• Automotive grade : AEC-Q100 Grade 2 for

infotainment products

ST can help you with wireless power integration in car infotainment,

come and visit us at our booth !

Product preview

STWBC

18Automotive Wireless Power Transmitter:

ASTWBCDigital controller for Wireless Battery Charger Transmitter

Automotive grade: Grade 2

Turn/key solution for quick design

* Customization possible via ST partnership

Available Peripherals for customization

• ADC with 10 bit precision

• UART

• I2C master fast-slow speed rate

• GPIOs

• Program memory: 32* Kbyte EEPROM (*available size for API

depends on selected FW)

Additional Application features:

• Low cost 2 layers PCBs

• Active object detection

• Graphical User Interface for application monitoring

• Evaluation board

Package:

VFQFPN32 5x5

STWBC_MC*

ASTWBC*

* Contact your local STMicroelectronics representatives for product information