prEN IEC 63758-5-6:2026

• Status: Not Published
• Publication Date: 23-Feb-2028
• Technical Committee: CLC/TC 100X - Audio, video and multimedia systems and equipment and related sub-systems
• Current Stage: 4020 - Enquiry circulated - Enquiry
• Start Date: 18-Sep-2026
• Completion Date: 18-Sep-2026
• Directive: 2014/53/EU - Directive 2014/53/EU of The European Parliament and of the Council of 16 April 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC
• Mandate: M/607 - COMMISSION IMPLEMENTING DECISION of C(2025)1207 on a Standardisation Request M/607 as regards charging interface and charging communication protocol for radio equipment capable of being recharged by means of wireless charging in relation with Article 3(4), sixth subparagraph, of Directive 2014/53/EU of the European Parliament and of the Council.
• Ref Project: oSIST prEN IEC 63758-5-6:2026 - Qi specification - Version 2.3 - Part 5-6: Mpp - Communications physical layer (Informative) (Fast Track)

prEN IEC 63758-5-6:2026 is a CLC/IEC draft in the Qi specification, Version 2.3, for the MPP communications physical layer. It specifies the low-level formats of data bits, bytes, and data packets, and it sets out the load-modulation and frequency-shift-keying behavior used by MPP Power Transmitters (PTx) and Power Receivers (PRx).

What does prEN IEC 63758-5-6:2026 specify?

prEN IEC 63758-5-6:2026 specifies the physical communications layer used in MPP mode, including the data-link framing used between the PTx and PRx. Clause 1 states that the document covers low-level packet structure, while Clause 2 introduces the communications physical layer and Clauses 3 and 4 cover the two signaling directions.

The document is organized as follows:

• Clause 1 - General: structure of the Qi specification, scope, compliance, references, and notation
• Clause 2 - Communications Physical Layer: overview of the MPP communication model
• Clause 3 - Frequency Shift Keying (FSK) from PTx to PRx
• Clause 4 - Amplitude Shift Keying (ASK) from PRx to PTx

In practice, this means the document is aimed at implementers who need to build or test interoperable MPP communication behavior, not just the power-transfer hardware around it. It defines how the packets are formatted and how the signal is carried on the power link.

What are the key requirements of prEN IEC 63758-5-6:2026?

prEN IEC 63758-5-6:2026 combines packet-format rules with transmitter and receiver behavior for both directions of communication. The most important points are the packet conventions in Clause 1, the FSK rules in Clause 3, and the ASK rules and performance limits in Clause 4.

General conventions that affect implementation

Clause 1.3 states that provisions are mandatory unless they are identified as recommended, optional, note, example, or informative. For an engineer, that means the wording matters: “shall” is a requirement, while “should” is guidance.

Clause 1.5 defines how numbers, tolerances, packet fields, text strings, and shorthand packet names are written. Numeric values are exact unless stated otherwise, packet fields use big-endian byte order, and text strings are stored in printable ASCII with NUL padding when needed. This matters because software, firmware, and test tools must parse packets the same way.

FSK from PTx to PRx

Clause 3 says the MPP Power Transmitter shall use Frequency Shift Keying (FSK) for communication to the Power Receiver. The transmitter uses 128 cycles of the power switching frequency for normal FSK transmission and 512 cycles for FSK responses to a CFG packet. It also sends a preamble of 4 ONE bits before every FSK data packet and uses the defined header, message, checksum, and response-pattern formats.

Clause 3 also adds MPP-specific behavior. The MPP Power Transmitter shall transmit the MPP ACK Pattern, and adjacent bytes in a packet shall run without a gap between the stop bit of one byte and the start bit of the next. For design work, this fixes timing and framing, so the receiver can lock onto the packet without ambiguity.

Clause 3.2 gives the operating-point details for 128 kHz and 360 kHz operation. It also states that the MPP Power Transmitter ignores requested FSK parameters in a CFG packet and uses the values defined in this part instead. This is important for interoperability because the receiver cannot rely on negotiating alternate FSK settings.

ASK from PRx to PTx

Clause 4 says the MPP Power Receiver shall use Amplitude Shift Keying (ASK) back to the Power Transmitter. The receiver changes its load on the power signal so that the transmitter sees a measurable change in capacitor voltage, either in magnitude or in phase. The document also allows a receiver to meet the magnitude condition in some positions or loads and the phase condition in others, as long as one of them is met in every combination.

Clause 4.2 describes two implementation styles. At 128 kHz, the PRx switches 33 nF communications capacitors and uses zero-voltage switching and fast turn-off behavior. At 360 kHz, it modulates electronic load current with a defined MOD_DEPTH and a selectable MOD_BASE. In practice, this tells the designer whether the implementation is capacitor-switching or current-modulation based.

Clause 4.2.2 describes the transmitter-side ASK receiver chain: differential amplifier, antialias filter, ADC, quadrature demodulation, low-pass filtering, decimation, and detector/receiver units. The text requires at least 10-bit ADC resolution and a sampling rate of roughly 10 times the relevant bandwidth. This matters because the receiver must capture the modulated signal cleanly enough to decode it under switching noise.

Clause 4.3 sets ASK performance conditions using the Test Power Transmitter (TPT) in the 2 x 2 mm MPP cylinder at 128 kHz and 360 kHz. For each frequency, the PRx must meet either an amplitude-and-SNR condition or a phase-and-SNR condition. For testing, this gives a clear pass/fail target for communication margin.

Clause 4.3.11 requires the Power Transmitter to receive and decode ASK transmissions from the Power Receiver without causing a disconnect when mated with a TPR. That is the practical interoperability target: communication must not interrupt the charging session.

What terms does prEN IEC 63758-5-6:2026 define?

• Power Transmitter (PTx) - the unit that sends power and carries the outbound FSK communication to the Power Receiver.
• Power Receiver (PRx) - the unit that receives power and sends back ASK communication by changing its load.
• Frequency Shift Keying (FSK) - the PTx-to-PRx method that encodes bits by changing the switching frequency.
• Amplitude Shift Keying (ASK) - the PRx-to-PTx method that encodes information by changing the load seen by the transmitter.
• Signal-to-Noise Ratio (SNR) - the noise metric used in ASK performance requirements to show how clearly the signal can be detected.
• Test Power Transmitter (TPT) - the reference transmitter used in ASK test conditions and performance checks.
• CFG packet - the packet type that triggers the longer FSK bit period used for certain responses.

Who uses prEN IEC 63758-5-6:2026?

Engineers designing Qi-compatible wireless chargers, receivers, and embedded control software use prEN IEC 63758-5-6:2026 to define packet timing, modulation behavior, and receiver architecture. Test engineers and certification teams use it to set up FSK and ASK checks, including the TPT-based performance conditions.

Quality managers and buyers use it when they need to confirm that a product implementation matches the MPP communications behavior expected by the Qi specification. The standard is most relevant to wireless power transfer products, especially mobile-device and charger applications that need reliable low-level communication on the power link.

Which standards are used with prEN IEC 63758-5-6:2026?

• ISO/IEC Directives, Part 2 - Clause 1.3 follows its rules for normative wording such as shall, should, may, and can.
• The Communications Physical Layer book - provides the shared bit encoding, byte encoding, packet fields, and response patterns that this part reuses.
• The MPP Communications Protocol book - is referenced for CFG packet behavior and related protocol details.
• The MPP Power Delivery book - is referenced for dithering and power-delivery behavior that can affect FSK receiver design.
• The Qi specification as a whole - provides the companion documents listed in Clause 1.1 and the shared packet vocabulary used across the family.

What does the prEN IEC 63758-5-6:2026 document contain?

The document contains a general section with compliance language, notation rules, packet-field conventions, and shorthand packet notation. It also includes system-model figures for FSK and ASK transmitters and receivers, showing how the PTx and PRx communicate over the power signal.

Table 1 sets out the verbal forms used in the specification, and Table 2 and Figure 1 explain how fields in a data packet are laid out. Table 3 gives MOD_BASE selection guidance for ASK operation.

Figures 2 through 11 show the MPP communications physical system model, FSK transmitter and receiver models, ASK modulator and receiver models, modulation trends, and representative waveforms. These figures are used to support design, simulation, and test development for MPP communications behavior.

SLOVENSKI STANDARD
01-november-2026
Specifikacija Qi - Različica 2.3 - 5-6. del: Mpp - Fizična raven komunikacije
(informativno) (hitri postopek)
Qi specification - Version 2.3 - Part 5-6: Mpp - Communications physical layer
(Informative) (Fast Track)
Ta slovenski standard je istoveten z: prEN IEC 63758-5-6:2026
ICS:
29.240.99 Druga oprema v zvezi z Other equipment related to
omrežji za prenos in power transmission and
distribucijo električne energije distribution networks
33.160.99 Druga avdio, video in Other audio, video and
avdiovizuelna oprema audiovisual equipment
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

100/4548/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 63758-5-6 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-09-18 2026-12-11
SUPERSEDES DOCUMENTS:
IEC TC 100 : AUDIO, VIDEO AND MULTIMEDIA SYSTEMS AND EQUIPMENT
SECRETARIAT: SECRETARY:
Japan Ms Mahiru Uehara
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 106,TC 108
ASPECTS CONCERNED:
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they
are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some Countries”
clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for
submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Qi Specification - Version 2.3 - Part 5-6: MPP - Communications physical layer (Informative) (Fast
Track)
PROPOSED STABILITY DATE: 2029
NOTE FROM TC/SC OFFICERS:
As this is a fast-track process offered by WPC, the Word file is not provided.

electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

QiSpecification
MPP–CommunicationsPhysical
Layer
Version2.3
PublishDate:08December2025
DISCLAIMER
Theinformationcontainedhereinisbelievedtobeaccurateasofthedateofpublication,butisprovided“asis”andmay
containerrors.TheWirelessPowerConsortiummakesnowarranty,expressorimplied,withrespecttothisdocument
anditscontents,includinganywarrantyoftitle,ownership,merchantability,orfitnessforaparticularuseorpurpose.
NeithertheWirelessPowerConsortium,noranymemberoftheWirelessPowerConsortiumwillbeliableforerrorsin
thisdocumentorforanydamages,includingindirectorconsequential,fromuseoforrelianceontheaccuracyofthis
document.Foranyfurtherexplanationofthecontentsofthisdocument,orincaseofanyperceivedinconsistencyor
ambiguityofinterpretation,contact:[e-mail].

Contents
1. General 5
1.1 StructureoftheQi Specification 5
1.2 Scope 6
1.3 Compliance 6
1.4 References 6
1.5 Conventions 7
1.5.1 Notationofnumbers 7
1.5.2 Tolerances 7
1.5.3 Fieldsinadatapacket 7
1.5.4 Notationoftextstrings 8
1.5.5 Short-handnotationfordatapackets 8
2. CommunicationsPhysicalLayer 9
2.1 Introduction 9
3. FrequencyShiftKeying(PTxtoPRx) 10
3.1 SystemModel 10
3.1.1 FSKModulator(PTx) 10
3.1.2 FSKReceiver(PRx) 11
3.2 FrequencyShiftKeyingSpecifications 13
3.2.1 PTxFSKSpec1 13
3.2.2 PTxFSKSpec2 13
3.2.3 PTxFSKSpec3 13
3.2.4 PTxFSKSpec4 13
3.2.5 PTxFSKSpec5 13
3.2.6 PTxFSKSpec6 13
3.2.7 PTxFSKSpec7 13
3.2.8 PTxFSKSpec8 13
3.2.9 PTxFSKSpec9 13
3.2.10 PTxFSKSpec10 14
3.2.11 PTxFSKSpec11 14
3.2.12 PTxFSKSpec12 14
3.2.13 PTxFSKSpec13 14
3.2.14 PTxFSKSpec14 14
3.2.15 PRxFSKSpec1 14
4. AmplitudeShiftKeying(PRxtoPTx) 15
4.1 ModulationScheme 15
4.2 SystemModel 16
4.2.1 ASKModulator(PRx) 16
4.2.2 ASKReceiver(PTx) 19
4.2.3 ASKModulationTrends 20
4.3 ASKSpecifications 22
4.3.1 PRxASKSpec1 22
4.3.2 PRxASKSpec2 22
4.3.3 PRxASKSpec3 22
4.3.4 PRxASKSpec4 22
4.3.5 PRxASKSpec5 22
4.3.6 PRxASKSpec6 22
4.3.7 PRxASKSpec7 22
4.3.8 PRxASKSpec8 22
4.3.9 PRxASKSpec9 22
4.3.10 PRxASKSpec10 23
4.3.11 PTxASKSpec1 23
4.4 Recommendations 24
4.4.1 PRxASKRecommendation1 24
4.4.2 PRxASKRecommendation2 24
4.4.3 PRxASKRecommendation3 24
4.4.4 PRxASK Recommendation4 24

1. General
TheWirelessPowerConsortium(WPC)isaworldwideorganizationthataimstodevelopandpromoteglobalstandards
forwirelesspowertransferinvariousapplicationareas.Animportantapplicationareacomprisesflat-surfacedevices
suchasmobilephonesandchargersoperatingatpowerlevelsupto25W.
1.1 StructureoftheQi Specification
Generaldocuments
l
Introduction
l
Glossary,Acronyms,andSymbols
l
TechnicalSystemOverview
l
PowerProfiles
Systemdescriptiondocuments
l
Mechanical,Thermal,andUserInterface
l
PowerDelivery
l
CommunicationsPhysicalLayer
l
CommunicationsProtocol
l
ForeignObjectDetection
l
NFCTagProtection
l
AuthenticationProtocol
l
MPPCommunicationsProtocol
l
MPPMagneticsDesign
l
MPP PowerDelivery
l
MPP CommunicationsPhysicalLayer
l
MPP ForeignObjectDetection
l
MPP DesignGuidelines(Informative)
l
MagneticCovers
l
ActiveAlignmentSystem
l
ThermalManagementProtocol
1.2 Scope
TheQiSpecification,MPPCommunicationsPhysicalLayer(thisdocument)definesthelow-level(physicallayerandthe
datalinklayer)formatsofdatabits,databytes,anddatapackets.Inaddition,itprovidesrequirementsandguidelines
forloadmodulationandfrequency-shiftkeying.
1.3 Compliance
AllprovisionsintheQiSpecificationaremandatory,unlessspecificallyindicatedasrecommended,optional,note,
example,orinformative.VerbalexpressionofprovisionsinthisSpecificationfollowtherulesprovidedinISO/IEC
Directives,Part2.
Table1-Verbalformsforexpressionsofprovisions
Provision Verbalform
requirement “shall”or“shallnot”
recommendation “should”or“shouldnot”
permission “may”or“maynot”
capability “can”or“cannot”
1.4 References
Forundatedreferences,themostrecentlypublisheddocumentapplies.ThemostrecentWPCpublicationscanbe
downloadedfromhttp://www.wirelesspowerconsortium.com.

1.5 Conventions
1.5.1 Notationofnumbers
l
Realnumbersusethedigits0to9,adecimalpoint,andoptionallyanexponentialpart.
l
Integernumbersindecimalnotationusethedigits0to9.
l
Integernumbersinhexadecimalnotationusethehexadecimaldigits0to9andAtoF,andareprefixedby"0x"
unlessexplicitlyindicatedotherwise.
l
SinglebitvaluesusethewordsZEROandONE.
1.5.2 Tolerances
Unlessindicatedotherwise,allnumericvaluesintheQiSpecificationareexactlyasspecifiedanddonothaveany
impliedtolerance.
1.5.3 Fieldsinadatapacket
Anumericvaluestoredinafieldofadatapacketusesabig-endianformat.Bitsthataremoresignificantarestoredata
lowerbyteoffsetthanbitsthatarelesssignificant.Table2andFigure1provideexamplesoftheinterpretationofsuch
fields.
Table2-Exampleoffieldsinadatapacket(table)
b b b b b b b b
7 6 5 4 3 2 1 0
B (msb)
B 16-bitNumericDataField (lsb)
B OtherField
(msb)
B 16-bitNumericDataField (lsb)
Field
Figure1-Examplesoffieldsinadatapacket

1.5.4 Notationoftextstrings
TextstringsconsistofasequenceofprintableASCIIcharacters(i.e.intherangeof0x20to0x7E)enclosedindouble
quotes(").Textstringsarestoredinfieldsofdatastructureswiththefirstcharacterofthestringatthelowestbyte
offset,andarepaddedwithASCIINUL(0x00)characterstotheendofthefieldwherenecessary.
EXAMPLE: Thetextstring“WPC”isstoredinasix-bytefieldsasthesequenceofcharacters'W','P','C',NUL,NUL,and
NUL.Thetextstring“M:4D3A”isstoredinasix-bytefieldasthesequence'M',':','4','D','3',and'A'.
1.5.5 Short-handnotationfordatapackets
Inmanyinstances,theQiSpecificationreferstoadatapacketusingthefollowingshorthandnotation:
/
Inthisnotation,referstothedatapacket'smnemonicdefinedintheQiSpecification,Communications
Protocol,andreferstoaparticularvalueinafieldofthedatapacket.Thedefinitionsofthedatapacketsin
theQiSpecification,CommunicationsProtocol,listthemeaningsofthemodifiers.
Forexample,EPT/ccreferstoanEndPowerTransferdatapackethavingitsEndPowerTransfercodefieldsetto0x01.

2. CommunicationsPhysicalLayer
2.1 Introduction
ThisbookdescribesthephysicalcommunicationslayerthatisimplementedinMPPandthecorrespondingspecifications
foranMPPPTxandPRx.
InMPPmode,thePTxcommunicatestothePRxbymodulatingtheinverterfrequencyandthereforethepowersignal
frequency.ThiscanbedemodulatedonthePRxaspartofthesynchronousrectificationprocess.ThePRxuses
backscattermodulationtocommunicatebacktothePTx.Forthispurpose,thePRxmodulatestheamplitudeofthe
powersignalbychangingitsload.ThePTxcandemodulatethissignalbymeasuringthevoltageacrosstheresonant
capacitor( ).AfigureofthesystemmodelisshowninFigure2.
Figure2-MPPCommsPhysicalSystemModel.

3. FrequencyShiftKeying(PTxtoPRx)
TheMPPsystemmodelusestheFSKmodulationbitencodingschemeasdefinedintheCommunicationsPhysicalLayer
book andusesthefollowingmodulationparameters:
Value
Parameter
MPP
MPP
(360kHzrampuppingand
(128kHzdigitalping)
powertransfer)
PowerFrequency( ) 127.772kHz 360kHz
ModulationFrequency( ) 125.435kHz 366.412kHz
NumberofSwitchingCyclesPerBit 512
(FollowingCFGpacketonly)
NumberofSwitchingCyclesPerBit 128
(followinganyASKpacketotherthanCFG)
3.1 SystemModel
3.1.1 FSKModulator(PTx)
ThesystemmodelFSKtransmitterispresentedinFigure3.Ingeneral,PowerTransmittervariesitsoperatingfrequency
totransmitdatatothePowerReceiver.
Whenoperatingat128kHz,thePTxperformsFSKmodulationbyswitchingbetweenthenominaloperatingfrequency,
,of127.772kHzandthemodulatedfrequency, ,of125.435kHz.
Whenoperatingat360kHz:
l thePTxperformsFSKmodulationbyswitchingbetweenthenominaloperatingfrequency, ,of360kHzand
themodulatedfrequency, ,of366.412kHz
l
frequencyditheringisused,witharepetitionlengthof16powerfrequencycyclesandadeviationof-7kHzto+7
kHz
l
thefrequencyditheringdeviationislargerthantheFSKmodulationdepth
l and valuesaretheaveragesmeasuredoveraperiodof16cycles

Figure3- SystemModelforFSKTransmitter.
3.1.2 FSKReceiver(PRx)
ThesystemmodelofaPRxFSKreceiverispresentedinFigure4.
Ingeneral,thePRxmeasuresthefrequencyofthereceivedACpowerbymeasuringthecycle-on-cycletimeofthepower
switchingfrequency.
Themeasuredcycletimesarethenprocessedinthedigitaldomain.Thesignalchainconsistsof:
l
amovingaveragefilterisusedtofilteroutnoise.Thelengthofthefilteris64cycles,whichisanexactmultipleof
themaximumditherperiod-16cycles.Thismeansthemovingaveragefilterwillbothattenuaterandomnoise
andremoveditheringsignals
l
thefilteredsignalisthenpassedtoadetector/receiverunit
l
finally,thereceivertakeswhicheverisavailable-andcorrect-firstfromtheMagnitudeandPhasedetector/
receiverunits.
Thedetector/receiverunit:
l
maybeimplementedinhardware,software,oramixtureofthetwo
l
removesDCcontentfromtheinputsignal
l
appliessymboldetectionfilters;thesedetectthespecificshapeofFSKsignalwaveformsandremoveasmuch
noiseaspossible
l
appliessomeformofsampletimingcontrolsuchastimecountingandpeakdetection
l
samplestheincomingdatastreamtoproduceastreamofindividualencodedbits
l
removesthedifferentialbi-phaseencoding
l
performspacketdecoding.
Figure4-SystemModelforFSKReceiver.
Inprinciple,theFSKdetectorelectronicscouldbeassimpleasacomparatorwhichcomparestheAC1orAC2signalto
somereference.
However,atlightload,thecoilcurrentwaveformsbecomedistortedbythepresenceofharmoniccontentdevelopedby
theinverter.Inparticular,the3rdharmonicofa360kHzpowerfrequency(1.08MHz)mayexcitearesonancewiththe
parallelcapacitorC requiredtoestablisha1MHzresonanceforBPPAnaloguePing(referto theMPPPowerDelivery
d
bookforfurtherinformation).ThiscancauseoscillationsofAC1andAC2nodevoltages,andgenerateextracrossing
eventsonthecomparatoroutputasshowninFigure5.
TheFSKreceivermustincludeappropriatecountermeasurestoaddressthissituation,whichcouldincludetheuseof
comparatorhysteresis,adaptivereference
...