Design of Automotive Chargersg gFor WPC 1504Charlie Wu

S e p t . 1 7 . 2 0 1 5

Distinguished Member of Technical Staff

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AgendaAgendaWireless Charging in AutomotiveAutomotive Wireless Charging ChallengesAutomotive Wireless Charging ChallengesAutomotive Wireless Transmitter Solution

DesignWireless Charging Software DesignQ&A

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Wireless Charging in Car

Toyota

Honda

Chrysler AudiAudi’s Phone Box

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Wireless Charging Challenges in Automotive

Foreign Object Detection• Foreign Object Detection :Selective and qualitative detection of foreign objects around the system (metallic or magnetic objects) is of key importance due to their ability to absorb energy from the wireless power supply field in the form of heat (parasitic heating) and possibly become a hazard.

CE4A (Consumer Electronics for Automotive)•CE4A (Consumer Electronics for Automotive)― No-Go for all automotive OEM’s:

Radio AM/FM band (AM band)Remote t key (Most systems operate inside existing Qi frequency range)Capacitive switchImmobilizerImmobilizerNFC

― Automotive key points:EnvironmentalHarsh operating temperature rangesHumidity and spill protectionVibration profilesThermal shock

•Shielding effectiveness:The shielding added under the primary and above the secondary is important for the safe operation of wireless power transfer. Without shielding, the magnetic field may interfere with the device or other objects; it may cause battery heating and may circulate current in metallic parts.

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Wireless charging Transmitter – A13 transmitter Litz Wire Coils

Key Features:

Compliant with Wireless Power Consortium (WPC) low power specifications to support up to 5W power transferI t t d di it l d d l tiIntegrated digital demodulationSupport free positioning multiple coils low power transmitter solutions using fixed frequency PWM controlSupport both Resonance Shift and Power Loss FOD methods

Support key FOB and AM band avoidance

Low standby power consumption

Automotive applications design

Support PMA SR1 specifications

AEC-Q100 grade 2 certification

Voltage/current/temperature protectionVoltage/current/temperature protection

Software based solution with Freescale embedded wireless charger software libraries to provide maximum design freedom and product differentiation FreeMASTER GUI tool to enable customization and calibration

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Got WPC Qi certification with WCT1001AVLH: 15010210HKG

Example of PCB type Coil (4 coils) –A33 Transmitter Type

4th coil

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How Freescale Solution Fits for Automotive (1/3)

• SafetySafety− Foreign object detection:

Support resonance shift method for FOD before power transferSupport power loss method for FOD during power transfer

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Support power loss method for FOD during power transferAdditional coils temperature protection

How Freescale Solution Fits for Automotive (2/3)

• Harsh Environment− Alignment Aids

S t i d t il d PCB t ilSupport wire-round type coils and PCB type coilsSupport multi-coil array for fee positioning alignment with large charging area Large z-gap up to 10mm

AEC Q100 certified product− AEC-Q100 certified product− Comprehensive system fault protection: voltage/current/temperature

protectionEmissions/Interferences• Emissions/Interferences− Fixed operating frequency to reduce the emission for wide frequency band − KeyFOB/Radio Interference

S t ti f d ift t d th i t f di t ifiSupport operating frequency drift to reduce the interference according to specific frequency band

− NFC co-existancePartner with Melexis to provide NFC solution for co-existance with WPC

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Partner with Melexis to provide NFC solution for co existance with WPC

How Freescale Solution Fits for Automotive (3/3)

• Low standby power consumption− Support touch sensor for ultra low standby power consumption

S G f− Support analog PING with intermittent controller deep sleep for low standby power consumption

• Vehicle InterfaceS f− Support wide support voltage rage from 9V to 16V

− Ignition interface designed− CAN communication interface

Support to add wireless charging into car network for better managementSupport software updating from HMI

• ProductibilityS ft b d l ti t il id t ti t t f t d i− Software based solution to easily provide automatic test feature during mass production and service

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Analog demodulation in wireless charging

Hardware demodulation circuit

Wireless Charging chipset

Coil current signal

TX Coil

chipset

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Digital demodulation in wireless charging- Low cost and Flexible

Sampling circuit

Coil current signal

WCT1xxxA

ADCDDM software

TX Coil

ADC software module

Benefit Tradeoff

BOM t d d S hi ti t d d d l ti l ithBOM cost reduced Sophisticated demodulation algorithms

PCB area reduced for more compatible applications DSP processing required

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Freescale Wireless Transmitter Software Structure

The basic kernel functions of wireless charging is packed as library form

The add-on/customized functions are provided as API interfaces suchas API interfaces such as FOD, Touch sensor, CAN, NFC, IIC, indicator/buzzer etc.

User is required to write his/her code for those user application code

Sample code projects will be provided for customer reference to speed the development time

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development time

Wireless Transmitter State Machine

SelectionRX removed

PiR t

Retry time expires No start bit and timeout

PingRetry

No packet and timeout

Iden and ConfigSet retry time 

according to error type

timeout

Error packet timeoutError protection

Power transfer

Close loop control

Error protection

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Software Development GUI Tool

Freescale wireless charging GUI tool is based on FreeMASTER, and provides: Configuration: System parameters, coil parameters and FOD parametersCalibration: Analog signal sensing coefficients, FOD algorithm coefficientsg g g gDebugging: System real-time status and variables

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WCT1000 / WCT1101* – Single Coil Transmitter IC

WCT1000WCT1000

CoreADC

InverterControl

Isense

Icoil Coil_PWM1

Drive_EN

CoilDis

Coil_PWM2

100MHz

Demod

Vsense

CommFOD

Hardware

100MHz core Support any 5W single coil type Demod

TouchSense

SDA

SCLT_IRQ

Support any 5W single coil typeRun-time calibration capableLow-power (< 30mA PID loop current)32QFN

S ft DebugSoftware

Closed loop PID algorithmForeign Object DetectionDigital demodulation

Optional

TDI

TMS

TCK

TDO

Reset

UA

RT_R

xU

AR

T_Tx

I2C for Touch Sense Interface (low power)

* WCT1101 - Premium

Program memory available to build & customize applicationAdditi l IO t d l tf biliti ( lti h l h

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Additional IOs to expand platform capabilities (e.g. multi-channel charger, NFC, etc.)64LQFP

WCT100xA – Automotive TransmitterHardware

Automotive-specific transmit controller solutionsAutomotive specific transmit controller solutionsSupports full H-bridge, multi-coil topologyStandard option provides additional programmability and communications interfacesPremium option expands on flash and SRAM for expanded programmability Multi-protocol capableWCT1001A & WCT1003A pin-pin compatible in the 64LQFP package

WCT100xADrive EN

Flash

WCT1001A & WCT1003A pin-pin compatible in the 64LQFP package

Coil1_PWM2

CoreADC Inverter

Control

Isense

Tsense

Vsense

Coil1_PWM1

Drive_EN

CoilDis

100MHz

Demod

Vsense

Comm

FOD

Coil1_En

Coil3_EnCoil2_En

SoftwareVoltage control algorithm

D b

TouchSense

LEDSPI 2SCI

DAC

CAN

g gForeign Object DetectionDigital demodulation

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Debug

Optional

LEDSPIx2SCICAN

Q & AQ & A

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