wireless charging in car infotainment - wireless … 2 •convergence of cars and smartphones is...
TRANSCRIPT
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