IEC 63254:2022
(Main)Management and interfaces for WPT - Device-to-device wireless charging (D2DWC) for mobile devices with wireless power TX/RX module
Management and interfaces for WPT - Device-to-device wireless charging (D2DWC) for mobile devices with wireless power TX/RX module
IEC 63254:2022 defines the specification and the control protocol of the D2DWC module for the use of wireless power TX and RX functions by a single device. The related antenna physical design examples for sharing information are presented in Annex A.
This document proposes the D2DWC module circuit requirement, which consists of the D2DWC main AP, D2DWC IC, the EMT/WPT antenna unit and the PMIC unit. In Clause 5, the register information and message protocols for WPT control are defined in order to implement the WPT TX function.
In this document, the interface and protocol in the wireless power process of the mobile device can be used in accordance with the corresponding wireless power transfer standard. Any wireless power transfer standard working within the 100 kHz to 350 kHz frequency range can be included in the scope of this document.
This document can be used for mobile wireless power transfer in mobile phones and other mobile devices, IoT devices, micro-sensor industries and related application fields.
Gestion et interfaces pour WPT - Chargement sans fil de dispositif à dispositif (D2DWC) pour dispositifs mobiles avec module TX/RX d'énergie sans fil
L'IEC 63254:2022 définit la spécification et le protocole de contrôle du module D2DWC pour l'utilisation des fonctions TX et RX d'énergie sans fil par un dispositif unique. Les exemples de conceptions physiques d'antenne connexes pour le partage d'informations sont donnés à l'Annexe A.
Le présent document établit les exigences relatives au circuit du module D2DWC, qui comprend l'AP D2DWC principal, l'IC D2DWC, l'unité d'antenne EMT/WPT et l'unité PMIC. L'Article 5 définit les informations de registre et les protocoles de message pour le contrôle WPT pour la mise en œuvre de la fonction TX WPT.
Dans le présent document, l'interface et le protocole du processus d'alimentation sans fil du dispositif mobile peuvent être utilisés conformément à la norme de transfert d'énergie sans fil correspondante. Toute norme de transfert d'énergie sans fil applicable dans la plage de fréquences comprise entre 100 kHz et 350 kHz peut être incluse dans le domaine d'application du présent document.
Le présent document peut être utilisé pour le transfert d'énergie sans fil dans les téléphones mobiles et autres dispositifs mobiles, dans les dispositifs d'IoT, les industries de microcapteurs et les domaines d'application connexes.
General Information
Standards Content (Sample)
IEC 63254 ®
Edition 1.0 2022-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Management and interfaces for WPT – Device-to-device wireless charging
(D2DWC) for mobile devices with wireless power TX/RX module
Gestion et interfaces pour WPT – Chargement sans fil de dispositif à dispositif
(D2DWC) pour dispositifs mobiles avec module TX/RX d'énergie sans fil
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IEC 63254 ®
Edition 1.0 2022-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Management and interfaces for WPT – Device-to-device wireless charging
(D2DWC) for mobile devices with wireless power TX/RX module
Gestion et interfaces pour WPT – Chargement sans fil de dispositif à dispositif
(D2DWC) pour dispositifs mobiles avec module TX/RX d'énergie sans fil
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.240.99; 33.160.01 ISBN 978-2-8322-5703-6
– 2 – IEC 63254:2022 © IEC 2022
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Operation scenarios . 8
4.1 Architecture . 8
4.2 Communication procedure for D2DWC . 9
4.2.1 General . 9
4.2.2 Total operation scenario of D2DWC . 9
4.2.3 TX operation scenario of D2DWC . 10
4.2.4 RX operation scenario of D2DWC . 11
5 Specifications and control protocol of D2DWC unit . 12
5.1 General control of a D2DWC unit of the TX-RX combined type . 12
5.1.1 General . 12
5.1.2 Purposes of WPT control of the D2DWC unit . 14
5.1.3 Operation control of the D2DWC unit . 14
5.2 Design guide for D2DWC TX-RX combined power transmitter . 17
5.3 Control protocol of D2DWC unit . 18
5.3.1 General . 18
5.3.2 WPT command . 19
5.3.3 D2DWC control . 20
5.3.4 Reply of D2DWC . 22
5.3.5 D2DWC parameter . 22
Annex A (informative) Antenna design guide for D2DWC TX-RX combined power
transmitter . 24
A.1 5-W-class WPT RX antenna . 24
A.1.1 General . 24
A.1.2 Antenna design guide . 24
A.1.3 Detailed specifications of circuit . 25
A.2 15-W-class WPT RX antenna design guide . 26
A.2.1 General . 26
A.2.2 Detailed specifications of circuit . 27
Annex B (informative) Regulation certification . 29
Bibliography . 30
Figure 1 – Overall architecture of the proposed EMT/WPT module. 8
Figure 2 – Operation scenario of D2DWC . 9
Figure 3 – TX operation scenario of D2DWC using battery power only . 10
Figure 4 – TX operation scenario of D2DWC using constant power supply . 11
Figure 5 – RX operation scenario of D2DWC . 12
Figure 6 – Wireless charging control architecture of the proposed standard . 13
Figure 7 – System operation efficiency . 14
Figure 8 – Operation diagram for D2DWC WPT . 14
Figure 9 – D2DWC TX operation voltage diagram . 15
Figure 10 – D2DWC TX operation voltage diagram . 16
Figure 11 – D2DWC RX operable voltage/current diagram . 17
Figure 12 – Major function blocks of D2DWC . 18
Figure 13 – D2DWC unit wireless power transfer and control protocol of the MCU . 19
Figure A.1 – D2DWC TX/RX antenna of the 5-W-class WPT RX standard . 24
Figure A.2 – D2DWC TX/RX circuit diagram of the 5-W-class WPT RX specifications . 25
Figure A.3 – D2DWC TX/RX antenna of the 15-W-class WPT RX specifications . 26
Figure A.4 – D2DWC TX/RX circuit diagram of the 15-W-class WPT RX specifications . 27
Table 1 – Specifications for the TX operation of D2DWC unit . 13
Table 2 – WPT CMD fields . 19
Table 3 – WPT subcommands. 19
Table 4 – D2DWC Control Command fields . 20
Table 5 – Determination of the D2DWC wireless power transfer operation . 20
Table 6 – Determination of battery charging amount . 20
Table 7 – D2DWC unit temperature limit . 21
Table 8 – D2DWC unit voltage limit . 21
Table 9 – D2DWC unit current limit . 21
Table 10 – Operation setting when wireless charging stops . 21
Table 11 – Operation setting when an error occurs . 22
Table 12 – Responses of D2DWC Control CMDs . 22
Table 13 – D2DWC parameter command fields . 22
Table 14 – Output voltage field of D2DWC . 22
Table 15 – D2DWC output current field . 23
Table 16 – Current temperature of D2DWC unit . 23
Table 17 – Output current of the battery terminal . 23
Table 18 – Output current of battery terminal . 23
Table 19 – Risk state field of the D2DWC unit . 23
Table 20 – Desired minimum voltage of the D2DWC unit . 23
Table A.1 – D2DWC TX/RX antenna parameters of the 5-W-class WPT RX
specifications . 25
Table A.2 – Electric characteristics of the D2DWC TX/RX circuit of the 5-W-class WPT
RX specifications . 26
Table A.3 – D2DWC TX/RX antenna parameters of the 15-W-class WPT RX
specifications . 27
Table A.4 – Electric characteristics of the D2DWC TX/RX circuit of 15-W-class WPT
RX specifications . 28
– 4 – IEC 63254:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MANAGEMENT AND INTERFACES FOR WPT –
DEVICE-TO-DEVICE WIRELESS CHARGING (D2DWC) FOR
MOBILE DEVICES WITH WIRELESS POWER TX/RX MODULE
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 63254 has been prepared by technical area 15: Wireless power transfer, of IEC technical
committee 100: Audio, video and multimedia systems and equipment. It is an International
Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
100/3799/FDIS 100/3820/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 63254:2022 © IEC 2022
MANAGEMENT AND INTERFACES FOR WPT –
DEVICE-TO-DEVICE WIRELESS CHARGING (D2DWC) FOR
MOBILE DEVICES WITH WIRELESS POWER TX/RX MODULE
1 Scope
This document defines the specification and the control protocol of the D2DWC module for the
use of wireless power TX and RX functions by a single device. The related antenna physical
design examples for sharing information are presented in Annex A.
This document proposes the D2DWC module circuit requirement, which consists of the D2DWC
main AP, D2DWC IC, the EMT/WPT antenna unit and the PMIC unit. In Clause 5, the register
information and message protocols for WPT control are defined in order to implement the WPT
TX function.
In this document, the interface and protocol in the wireless power process of the mobile device
can be used in accordance with the corresponding wireless power transfer standard. Any
wireless power transfer standard working within the 100 kHz to 350 kHz frequency range can
be included in the scope of this document.
This document can be used for mobile wireless power transfer in mobile phones and other
mobile devices, IoT devices, micro-sensor industries and related application fields.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
D2DWC
device-to-device wireless charging
wireless charging technology that uses a magnetic field-transmission function between mobile
devices, which can simultaneously perform wireless power TX and RX functions
3.1.2
D2DWC unit
IC that enables wireless power transmission/reception, and includes a magnetic
field-transmission function, mux, which allows the selection of WPT TX, and a transmission
inverter
3.1.3
WPT
wireless power transfer
technology that wirelessly sends energy to a load with no transmission line by converting
electric energy to electromagnetic waves
Note 1 to entry: To convert electric energy to electromagnetic waves, the electric energy is converted to RF signals
of a specific frequency and the energy is transmitted through the electromagnetic waves generated from them.
3.1.4
EMT
elective magnetic transmission
technology for transmitting elective magnetic waves and is currently used to create and send
magnetic waves for magnetic billing service of mobile phones
3.1.5
PMIC
power-management IC
device for managing battery charging, which includes a boost function
3.1.6
SPI
serial peripheral interface
synchronized serial data connection standard for operation in full-duplex communication mode
3.1.7
UART
universal asynchronous receiver/transmitter
device for receiving and sending data after converting parallel data to serial data
3.1.8
I C Bus
inter-integrated circuit bus
protocol for transmitting clocks, data, and commands
3.1.9
WPC Class 0 specification
specification used to load the battery of devices such as mobile phones, tablets, and small
accessories
Note 1 to entry: It has a maximum transmission power of 15 W.
Note 2 to entry: Power class 0 is defined by the WPC (World Power Consortium).
3.2 Abbreviated terms
WPT wireless power transfer
TX transmitter
RX receiver
RFU reserved for future use
MCU micro controller unit
– 8 – IEC 63254:2022 © IEC 2022
4 Operation scenarios
4.1 Architecture
This document proposes the physical definition and control information of modules for wireless
power transfer (WPT) between mobile devices that are operated by batteries instead of a
constant power supply and simultaneously support wireless power TX and RX. The total
architecture for the D2DWC technical standard proposed herein is shown in Figure 1.
To implement the features of the D2DWC, the following components are required:
a) D2DWC unit for performing magnetic field transmission function and wireless charging
TX/RX among mobile devices,
b) PMIC unit for battery charging,
c) EMT/WPT antenna unit for both EMT function and WPT TX/RX, and
d) microcontroller unit (MCU) for monitoring and controlling the D2DWC unit.
Among these components, the D2DWC unit consists of an EMT module, a WPT TX/RX module,
an EMP/WPT TX mux, and a power amp module. The EMT module can control and transmit
magnetic waveforms, and uses the same bandwidth as that of the frequencies specified in the
WPT for use in billing services, etc. The WPT TX/RX module has the functions to perform
wireless power transfer and reception. For WPT, it determines which magnetic field waveform
to send through the EMT module and mux. The EMT/WPT TX mux selects the waveform after
selecting the EMT and WPT TX signals. Finally, the power amp module sends the magnetic
field waveforms during EMT or WPT TX.
In order to examine each IC and module, for WPT, the D2DWC unit uses the mux to select and
send EMT and WPT TX, and a transmission inverter to generate and transmit magnetic fields,
which is shared between EMT and WPT. Furthermore, the WPT module can selectively perform
the TX/RX function. Outside of the D2DWC unit, there is one EMT/WPT antenna that shall be
used for three functions, for which the EMT and WPT functions shall be performed with the
same frequency. The antenna is shared for EMT and WPT functions, but the antenna can be
switched selectively depending on the EMT frequency. At a given frequency, the same antenna
may be used for both EMT and WPT TX. The optional EMT antenna is indicated to show the
selective change in the antenna length according to the impedance matching between the TX
and RX. Finally, the D2DWC unit is externally connected to the PMIC for battery charging, and
battery charging/discharging occurs during wireless power transfer and reception. Information
related to regulation and certification is presented in Annex B.
Figure 1 – Overall architecture of the proposed EMT/WPT module
4.2 Communication procedure for D2DWC
4.2.1 General
In this document, WPT can be controlled in accordance with the WPT standard used by the
user, and the class 0 WPT in the WPC standard is used as an example. For this case, the total
operation procedure of the D2DWC and the WPT TX/RX operations are presented in 4.2.
4.2.2 Total operation scenario of D2DWC
The total operation scenario of D2DWC is shown in Figure 2. The user first makes contact
between the coil parts of the TX and RX devices to perform WPT. The D2DWC then sends a
command to drive the WPT function to the D2DWC unit connected via the I C interface. The
D2DWC unit reports the current charging amount to the user, who checks the charging amount
of the device's battery and determines the desired charging amount and speed. Once charging
starts, the WPT TX device draws power from the battery and applies power to the WPT TX coil
and the power is cut off in the RX coil. Wireless charging is performed between the WPT TX
and RX devices, which are controlled in accordance with the mobile TX/RX combined device
environment proposed in this document. Finally, when the power is transmitted for the amount
set in the command, wireless charging is stopped in the WPT TX.
Figure 2 – Operation scenario of D2DWC
– 10 – IEC 63254:2022 © IEC 2022
4.2.3 TX operation scenario of D2DWC
The TX operation scenarios of D2DWC can be classified depending on the use of the boost
circuit of the PMIC module in the mobile device. Figure 3 illustrates the case of using battery
power only for the TX operation of D2DWC.
① When the start of WPT is notified by sending the WPT command to the D2DWC unit, the D2DWC operates in TX
mode.
② The D2DWC unit checks the battery connection to the PMIC interface and draws power for WPT.
③ The D2DWC unit carries out power transfer and communication to the RX through the TX coil in accordance with
the WPT standard.
④ Once the power specified in the WPT command is transmitted, the D2DWC unit stops sending power.
Figure 3 – TX operation scenario of D2DWC using battery power only
The second case of WPT TX operation is to supply constant power to the PMIC module in the
mobile device. Faster and more stable wireless charging is possible when constant power is
supplied. The TX operation scenario using a constant power supply is illustrated in Figure 4.
The difference from the case of using the battery circuit only is that the battery circuit is directly
blocked for wireless charging in the PMIC.
① The WPT command is sent to the D2DWC unit to indicate the start of wireless charging, and the D2DWC operates
in TX mode.
② When wireless charging command is issued to the D2DWC unit, the PMIC directly blocks the direct connection
of the battery power.
③ The boost circuit of the PMIC powers on.
④ The boosted power is input to Vext of the D2DWC unit, preparing for wireless charging.
⑤ The D2DWC unit carries out power transfer and communication to the RX through the TX coil in accordance with
the WPT standard.
⑥ When the specified amount of power has been transmitted in the WPT command, the D2DWC unit stops power
transfer.
Figure 4 – TX operation scenario of D2DWC using constant power supply
4.2.4 RX operation scenario of D2DWC
The RX operation scenario of D2DWC is illustrated in Figure 5. The D2DWC unit is always
waiting in RX mode until it receives a separate wireless charging command.
– 12 – IEC 63254:2022 © IEC 2022
① When power reception and communication occur in TX mode, the D2DWC unit starts preparing to receive wireless
power.
② When the power stabilizes, the Vout terminal outputs power.
③ Battery charging begins through the charger IC.
④ Charging is carried out until power transfer from the TX stops.
Figure 5 – RX operation scenario of D2DWC
5 Specifications and control protocol of D2DWC unit
5.1 General control of a D2DWC unit of the TX-RX combined type
5.1.1 General
To aid in understanding, this Clause 5 uses the class-0 specification of the WPC standard and
the PMA TX version 1.2 standard as examples. The D2DWC unit, which supports wireless power
TX/RX in a single device, requires additional control compared to class-0 of the WPC standard.
The D2DWC unit performs WPT in accordance with the WPT standard, but if the TX and RX
are combined in one device, conditions such as the voltage, current, and temperature vary and
are controlled by the MCU. The D2DWC unit reports the current state to the MCU while carrying
out message and data TX and RX for WPT. The MCU monitors the WPT of the D2DWC and
stops WPT if the device operates within the scope specified in this document. The overall
architecture is shown in Figure 6. During the WPT, the device operates in accordance with the
WPT standard. When the D2DWC unit is used, the operations shall be controlled with more
detailed specifications because the unit combines WPT TX and RX. This can be controlled by
any control unit that can transmit messages, such as I2C, SPI, or UART. In this document, a
control protocol using I2C is presented as an example in 5.3.
Figure 6 – Wireless charging control architecture of the proposed standard
The specifications when the D2DWC IC is operated in TX mode are listed in Table 1. The
specifications for operation based on experimental values were established in accordance with
the specifications of EMT TX and WPC TX class-0 of mobile devices and the PMA TX version
1.2. Furthermore, the system operation efficiency defined in this document is presented in
Figure 7, which is defined by the ratio of the TX input power to the RX output power.
In this document, the specifications of the D2DWC unit are redefined for medium-power
operation of up to 15 W to support charging from a notebook computer to a mobile phone and
fast charging for mobile devices. Furthermore, to support the PMA standard, which is a de facto
standardization organization, the frequency operation of 100 kHz to 350 kHz, which is a range
usable within 400 kHz in the EMT TX module, is redefined.
Table 1 – Specifications for the TX operation of D2DWC unit
PMA TX
D2DWC
EMT TX WPC TX (Example) version 1.2
(TX mode)
(Example)
Min. 100 KHz 80 KHz 100 KHz
Carrier 118 kHz to 153 kHz
frequency 277 kHz to 357 kHz
Max. 350 KHz 210 KHz 200 KHz
Min. 2 V 3 V 2 V 2 V
AC drive voltage
Avg. 5 V 5 V - -
(peak to peak)
Max. 12 V - 24 V 12 V
Input current Max. 1,5 A 2 A 2 A 1,5 A
Min. 2 W 2 W 7,5 W 7,5 W
Transmit power
Max. 15 W 10 W 20 W 15 W
System
Min. 40% 50% 65% 60%
efficiency
−20 °C −40 °C -20 °C
Min. −40 °C
(TX surface) (TX surface) (FOD)
Temperature
limit
50 °C 60 °C 60 °C
Max. 60 °C
(TX surface) (TX surface) (FOD)
– 14 – IEC 63254:2022 © IEC 2022
Figure 7 – System operation efficiency
5.1.2 Purposes of WPT control of the D2DWC unit
The operation control of the D2DWC unit that combines TX and RX in one device has the
following purposes:
a) protect the D2DWC unit from overvoltage, overcurrent, and over-temperature;
b) operate the D2DWC unit within a smaller range than the range specified in the document
based on WPC standard class-0 and PMA TX version 1.2;
c) control the output power to maximize the power consumption efficiency or the total system
efficiency.
5.1.3 Operation control of the D2DWC unit
5.1.3.1 General
The MCU controls the WPT of the D2DWC unit for WPT of the D2DWC, as shown in Figure 8.
Because the D2DWC unit has special voltage, current, and temperature ranges, the WPT is
stopped by force in an abnormal state, which can be regarded as a system error even if the
device is operating normally.
Figure 8 – Operation diagram for D2DWC WPT
– D2DWC parameter settings state: after power is supplied to the D2DWC, it is in the self-
test and adjustment state.
– D2DWC communication state: after the settings are communicated between TX and RX,
they prepare for WPT.
– D2DWC WPT state: the rectifier voltage state of the RX is continuously checked and WPT
is performed within the specified range of the D2DWC.
5.1.3.2 Operating voltage, current, and temperature conditions of the D2DWC unit in
TX mode
The D2DWC unit operates in special conditions that are different from those specified in WPC
standard class-0 (fast charging)/PMA TX version 1.2 because the D2DWC unit combines WPT
TX and RX. In the case of D2DWC TX, the operation threshold voltage of the AC driver is 12 V,
and the average operation power of the transmitter shall be 15 W. The operation voltage
diagram for D2DWC TX is shown in Figure 9. The operable voltage range of the TX is 3 V to
12 V, which was established based on the experimental values of the D2DWC operation.
Furthermore, the operation voltage-current diagram for D2DWC TX is shown in Figure 10. The
operation current range shall be 0,6 A to 2,0 A, and the maximum output power shall be 20 W
or less.
Figure 9 – D2DWC TX operation voltage diagram
– 16 – IEC 63254:2022 © IEC 2022
Figure 10 – D2DWC TX operation voltage diagram
Furthermore, the MCU continuously checks the temperature of the D2DWC unit to prevent
abnormal operation in a system-error state. The normal operation of the D2DWC unit can be
guaranteed within the operable temperature range of −20 °C to 50 °C.
5.1.3.3 Operating voltage, current, and temperature conditions of the D2DWC unit in
RX mode
When the D2DWC unit operates in RX mode, the operation threshold voltage shall be 8 V and
the threshold current shall be 1,2 A. The D2DWC RX operating voltage and current diagram is
shown in Figure 11. The rectified voltage and current ranges in which the receiver can operate
are 1,5 V to 8 V and 0,2 A to 1,2 A, respectively.
Figure 11 – D2DWC RX operable voltage/current diagram
5.2 Design guide for D2DWC TX-RX combined power transmitter
The production of a circuit and antenna in a mobile device with a built-in D2DWC unit that
supports WPT TX and RX in a single device requires more concrete specifications. Although
the D2DWC unit performs WPT in accordance with the WPC and PMA standard, the circuit
configuration and antenna design conditions vary when the TX and RX are combined in one
device. This subclause presents a design guide for the circuit and the antenna in a device where
the TX and RX functions of WPT are combined.
The power transmitter of the D2DWC proposed in this document consists of two major function
blocks, as shown in Figure 12. The first block is the power conversion unit and the second block
is the communication and control unit.
– 18 – IEC 63254:2022 © IEC 2022
Figure 12 – Major function blocks of D2DWC
The power conversion unit is an analogue component of the circuit. It converts the DC input to
AC waveforms, and also includes an antenna that consists of a capacitor and an inductor.
Furthermore, it detects the voltage and current in the antenna. The communication and control
unit is a digital logic component that controls the operation of the total system in WPT, in
accordance with the D2DWC control protocol.
5.3 Control protocol of D2DWC unit
5.3.1 General
In the D2DWC wireless power transfer, TX and RX are included in the same device. When the
TX receives a WPT command, it performs WPT while continuously exchanging data with the
MCU. The MCU and the D2DWC unit are connected via I C. In accordance with the protocol
defined in this document, the MCU monitors and controls the state through the read command
during the WPT process. The total information acquisition and control process of the D2DWC
WPT is shown in Figure 13. Whenever a command is transferred from the MCU to the D2DWC
unit, the response and current state are reported to the MCU. After receiving the response and
state information of the D2DWC unit, the MCU continuously sends control commands to the
D2DWC unit to determine the state of WPT.
Figure 13 – D2DWC unit wireless power transfer and control protocol of the MCU
Upon receiving the WPT command, the D2DWC unit continuously transfers its battery and load
information, and according to this, the MCU controls WPT in real time.
5.3.2 WPT command
This is a command that the MCU issues to the D2DWC unit to start WPT. After this, the MCU
continuously receives and sends information required for the D2DWC WPT and controls the
power to be transmitted. The total WPT command fields are outlined in Table 2 and the WPT
subcommands are listed in Table 3. This document uses the I C protocol for controlling the
D2DWC unit, but any protocol that supports a serial interface can be used.
Table 2 – WPT CMD fields
WPT
WPT command
I C slave address
command classification
# of bits 8 4
description IC type 0001
Table 3 – WPT subcommands
WPT subcommand Code Length (bits)
D2DWC WPT start 0001 12
D2DWC control 0010 70
Reply of
0011 20
D2DWC
D2DWC
0100 84
parameter
– 20 – IEC 63254:2022 © IEC 2022
5.3.3 D2DWC control
These WPT commands are issued by the MCU to the D2DWC unit to define the start, stop, and
other operations of WPT. The D2DWC unit continuously sends the voltage, current, and
temperature information to the MCU. The MCU monitors the D2DWC information and wireless
power state, and controls the D2DWC WPT in real time through these commands. The fields of
the D2DWC control commands are listed in Table 4 and the responses to the D2DWC control
commands are listed in Table 12. The D2DWC unit shall continuously receive the commands of
the MCU after the start of WPT, and the WPT is immediately stopped if it does not receive
commands for 50 ms.
Table 4 – D2DWC Control Command fields
D2DWC WPT Determination of Determination of
D2DWC unit
I C slave
control command D2DWC WPT battery charging
address temperature limit
CMD classification operation amount
Number of bits 8 4 4 8 8
description IC type 0010 Table 5 Table 6 Table 7
SSN dynamic Operation setting Operation setting
D2DWC unit D2DWC unit
parameter when wireless when an error CRC operation bit
voltage limit current limit
command charging stops occurs
Number of bits 8 8 3 3 16
Description Table 8 Table 9 Table 10 Table 11 CRC-16
Determination of D2DWC WPT operation: this field controls the current WPT of D2DWC based
on the information that the MCU received from the D2DWC unit.
Table 5 – Determination of the D2DWC wireless power transfer operation
Bit field 3 2 1 0
Continue WPT or
Index Output adjustment command
not
111 = RFU
110 = RFU
101 = Maximum allowable power
1 = Continue WPT
100 = 80 % of maximum allowable power
Description (Default value)
011 = 60 % of maximum allowable power (Default value)
0 = Stop WPT
010 = 40 % of maximum allowable power
001 = 20 % of maximum allowable power
000 = Minimum allowable power
Determination of battery charging amount: this field defines how much to charge the RX device
after the MCU consumes the charge battery amount of the D2DWC unit. Each bit represents a
difference of 0,5 %. Setting 0 indicates 0 % charging and 200 indicates 100 % charging. Greater
values indicate the RFU state.
Table 6 – Determination of battery charging amount
Bit field 8
Index The charging amount
0 to 200 = 0 % to 100 %
Description 201 to 255 = RFU
(Default value = 8'd100)
D2DWC unit temperature limit: this filed defines the temperature allowed in the D2DWC unit.
Each bit represents a difference of 5 °C. A setting of 0 indicates -20 °C, and 240 indicates 50 °C.
Greater values indicate the RFU state.
Table 7 – D2DWC unit temperature limit
Bit field 8
Index The allowable temperature
0 to 100 = −20 °C to 50 °C
Description 101 to 255 = RFU
(Default value = 8'd50)
D2DWC unit voltage limit: this field defines the Vext allowed in the D2DWC unit. Each bit
represents a difference of 0,1 V. A setting of 0 indicates 0 V, and 200 indicates 20 V. Greater
values indicate the RFU state.
Table 8 – D2DWC unit voltage limit
Bit field 8
Index The allowable voltage
0 to 200 = 0 V to 20 V
Description 201 to 255 = RFU
(Default value = 8'd100)
D2DWC unit current limit: this field defines the Iext allowed in the D2DWC unit. Each bit
represents a difference of 0,05 A. A setting of 0 indicates 0 A, and 200 indicates 10 A. Greater
values indicate the RFU state.
Table 9 – D2DWC unit current limit
Bit field 8
Index The allowable voltage
0 to 200 = 0 A to 10 A
Description 201 to 255 = RFU
(Default value = 8'd00)
Operation setting when wireless charging stops: sets the operation when the WPT stops in the
D2DWC unit due to an error, etc.
Table 10 – Operation setting when wireless charging stops
Bit field 2 1 0
Index Operation setting when wireless charging stops
100–111 = RFU
011 = Warning
010 = Retrial
Description
001 = Retrial after warning
000 = Stop after warning
(Default value = 3'b000)
– 22 – IEC 63254:2022 © IEC 2022
Operation setting when an error occurs: sets the operation when an error occurs i
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