oSIST prEN IEC 63758-13:2026

• Status: Not Published
• Public Enquiry End Date: 29-Nov-2026
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• ICS: 33.160.99 - Other audio, video and audiovisual equipment
• ICS: 35.200 - Interface and interconnection equipment
• Technical Committee: AVM - Audio, video and multimedia systems and equipment
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 28-Sep-2026
• Due Date: 15-Feb-2027
• 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: prEN IEC 63758-13:2026 - Qi specification - Version 2.3 - Part 13: Thermal management protocol (Fast Track)

oSIST prEN IEC 63758-13:2026 is a CLC/IEC committee draft for vote in the Qi Specification, Version 2.3, Part 13. It specifies the thermal management protocol for Qi wireless power transfer, including the messages and operating rules used to support active cooling between PRx and PTx devices. In practice, it is the part to read when a design needs cooling negotiation, temperature-based power reduction, or cloak-phase protection.

What does oSIST prEN IEC 63758-13:2026 specify?

oSIST prEN IEC 63758-13:2026 defines the requirements for thermal management and the related protocol needed to support active cooling. It is organized as a short technical part of the Qi Specification, with general rules, an introduction, protocol operation, requirements, and message definitions.

The document is structured as follows:

• Clause 1 covers general rules, compliance language, notation, and packet conventions.
• Clause 2 introduces active cooling and automatic cooling.
• Clause 3 describes how thermal management operates between PRx and PTx.
• Clause 4 states the formal requirements applied when the PTx is mated to TPR#MPP-THERMAL-PUCK.
• Clause 5 defines the thermal-management data streams and messages.

The focus is on thermal control during wireless power transfer, especially when cooling support is available and when temperature limits must be enforced by protocol action.

What are the key requirements of oSIST prEN IEC 63758-13:2026?

oSIST prEN IEC 63758-13:2026 sets out how a Qi system must negotiate, monitor, and respond to thermal risk. The most important points are the control flow, the thermal thresholds, the cooling-level rules, and the message set used to carry them.

Compliance language and control flow

Clause 1.3 says that provisions are mandatory unless they are marked as recommended, optional, note, example, or informative. This matters because implementers need to separate testable requirements from guidance, and it tells readers how to interpret the words used throughout the part.

Clause 3.1 defines three thermal-management operations:

• cooling capability identification
• cooling level selection
• cooling status change

In practice, a PRx can ask what cooling the PTx supports, request a chosen level, and react when the PTx reports a change in capability.

Thermal thresholds and staged response

Clause 3.2 uses two thermal thresholds, T1 and T2. T1 is the soft threshold that calls for preventive action, such as lowering negotiated power or increasing active cooling, while T2 is the hard threshold that leads to cloak phase and interruption of power transfer if the earlier action is not enough.

That staged behavior matters because it gives the system time to react before shutdown is needed. Instead of a single trip point, the protocol supports progressive mitigation.

PRx-initiated and PTx-initiated management

Clause 3.3 describes PRx-initiated thermal management when active cooling is supported. The PRx queries cooling capability, checks the current and maximum cooling level, and can request changes while the PTx confirms whether the request succeeded.

Clause 3.4 covers PTx-initiated thermal management when active cooling is not relied on. If the PTx reaches its thermal limits, it can request a lower transferred power level or ask to enter cloak phase. In practice, this gives the transmitter a fallback path when its own thermal margin becomes too small.

Thermal limits for the TPR#MPP-THERMAL-PUCK

Clause 4.1 sets thermal limits for the TPR#MPP-THERMAL-PUCK during power transfer. It distinguishes between the absolute interface temperature limit and the allowed temperature rise under different load-power conditions, and it also gives a separate limit for cloak phase.

For implementers, this means thermal verification must be tied to the operating state, not just to one nominal power point. The transmitter has to prove that its interface stays within the relevant limit while delivering power.

Automatic cooling and cooling-level behavior

Clause 4.2 says that an APTx that only supports automatic cooling shall not advertise support for the thermal-management data stream. That prevents a receiver from trying to negotiate a cooling function that the transmitter does not expose.

Clause 4.3 requires cooling-level monotonicity. A higher cooling level must mean higher cooling intensity, except for level 0, which is automatic. This makes the scale predictable for control software, testing, and interoperability checks.

Data streams, packets, and responses

Clause 5 defines the thermal-management messages exchanged by PRx and PTx. The thermal control traffic uses a dedicated data stream, and the messages include requests for cooling information, requests to set cooling parameters, capability reports, parameter responses, and error responses.

In practice, the receiver and transmitter need matching packet handling so that cooling requests are acknowledged, rejected, or updated in a consistent way.

What terms does oSIST prEN IEC 63758-13:2026 define?

oSIST prEN IEC 63758-13:2026 uses a small set of thermal-control terms that matter for implementation and testing.

• Active cooling - A cooling method that lowers the interface surface temperature while consuming power itself, such as a fan.
• Automatic cooling - A cooling mode controlled by the PTx thermistors and cooling system without relying on the thermal-management protocol.
• T1 - The primary soft thermal threshold that triggers early preventive action.
• T2 - The secondary hard thermal threshold that leads to cloak phase if the earlier response is not enough.
• Cloak phase - A protective phase in which power transfer is interrupted to protect the system from further temperature rise.
• Cooling level - The selected level used to adjust cooling intensity; level 0 is automatic, while higher levels are PRx-controlled.
• Cooling capability - The cooling support a PTx can report to a PRx, including the maximum level it can provide.
• Thermal risk - The condition in which rising temperature must be mitigated to protect operation, safety, or battery life.

Who uses oSIST prEN IEC 63758-13:2026?

oSIST prEN IEC 63758-13:2026 is used by teams that design, integrate, test, and qualify Qi wireless power products. It is especially relevant where power transfer above 15 W can create heat that must be managed by cooling control or power reduction.

Typical users include:

• product designers of Qi chargers, receivers, and accessories
• firmware and protocol engineers implementing PRx and PTx message handling
• thermal engineers sizing fans, thermistors, and control logic
• test laboratories checking thermal behavior, message exchange, and cloak-phase response
• quality managers and buyers comparing whether a product supports active cooling or only automatic cooling

Which standards are used with oSIST prEN IEC 63758-13:2026?

oSIST prEN IEC 63758-13:2026 relies on the Qi Specification framework and points readers to related parts for packet and transport behavior. The document also uses the general IEC drafting rules for compliance language.

• ISO/IEC Directives, Part 2 - provides the meaning of shall, should, may, and can as used in the provisions.
• Qi Specification, Communications Protocol - provides the packet mnemonics and shorthand notation used in this part.
• Qi Specification, MPP Communications Protocol - provides details for simultaneous auxiliary data transport (SADT), which this part references.

What does the oSIST prEN IEC 63758-13:2026 document contain?

oSIST prEN IEC 63758-13:2026 contains the rules and packet definitions needed to implement thermal management in Qi wireless power transfer. It includes conventions for numbers, tolerances, bit fields, text strings, and data-packet shorthand, so implementers can parse the protocol consistently.

It also contains the operational model for active cooling and automatic cooling, including PRx-initiated and PTx-initiated strategies. The figures illustrate threshold behavior, cooling-capability changes, and example temperature profiles.

The message section defines the cooling control data stream and the PRx and PTx message structures for capability requests, cooling parameter setting, status reporting, and error reporting. These definitions are the basis for implementation, test cases, interoperability checks, and protocol debugging.

SLOVENSKI STANDARD
01-november-2026
Specifikacija Qi - Različica 2.3 - 13. del: Protokol za upravljanje s toploto (hitri
postopek)
Qi specification - Version 2.3 - Part 13: Thermal management protocol (Fast Track)
Ta slovenski standard je istoveten z: prEN IEC 63758-13:2026
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.

100/4539/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 63758-13 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 13: Thermal management protocol (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
ThermalManagementProtocol
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 4
1.1 StructureoftheQi Specification 4
1.2 Scope 5
1.3 Compliance 5
1.4 References 5
1.5 Conventions 6
1.5.1 Notationofnumbers 6
1.5.2 Tolerances 6
1.5.3 Fieldsinadatapacket 6
1.5.4 Notationoftextstrings 7
1.5.5 Short-handnotationfordatapackets 7
2. Introduction 8
2.1 ActiveCooling 8
2.2 AutomaticCooling 8
3. ThermalManagementProtocol 9
3.1 Operations 9
3.2 ThermalThresholds 10
3.3 PRx-InitiatedThermalManagement 11
3.4 PTx-InitiatedThermalManagement 13
4. Requirements 15
4.1 TTHM001-TemperatureLimits 15
4.2 TTHM002-AutomaticCooling 15
4.3 TTHM003-CoolingLevelMonotonicity 15
5. DataStreamsandMessages 16
5.1 CoolingControlDataStream 16
5.2 PRxMessages 17
5.2.1 GetCoolingInfo-GET_COOLING_INFO-(0x1) 18
5.2.2 SetCoolingParameters-SET_COOLING_PARAM-(0x2) 19
5.3 PTxMessages 20
5.3.1 CoolingInfo-COOLING_INFO-(0x1) 21
5.3.2 CoolingParameterResponse-COOLING_PARAM_RSP-(0x2) 22
5.3.3 ErrorResponse-ERR_RSP-(0xE) 23

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,ThermalManagementProtocol(thisdocument)definestherequirementsforthermalmanagement,
andtherelatedprotocolnecessarytosupportactivecooling.
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. Introduction
IncreasedheatgenerationisaknownissueduringpowertransferathigherWattages.APTxproductdesignedtoenable
powertransferabove15Wneedstomeetthermalrequirementstoensurepowertransferefficiency,andpreserve
batterylife;usercomfortandsafetyarealsoimportantconsiderations.
2.1 ActiveCooling
Onethermalmanagementsolutionisactivecooling,whichreferstoanycoolingmethodthatreducesthesurface
temperatureattheinterfacesurfaceofamatedPTxproductandPRxproduct,whilstitselfconsumingpower,e.g.afan.
Adjustablecoolinglevelsandthermalprotocolallowforproactivethermalmanagement,optimisingwirelesspower
transfer.
2.2 AutomaticCooling
TheautomaticcoolingfeatureofaPTxdoesnotrelyonthermalmanagementprotocol.PTxshoulduseitsbuilt-in
thermistorstomonitorthesurfacetemperaturethatisincontactwiththePRx,andautomaticallyadjustsitscooling
system(e.g.fan)tokeepthecontactsurfacewithinanappropriatethreshold.

3. ThermalManagementProtocol
3.1 Operations
Thissectionoutlinestheprotocoloperationsthatcanbeusedinthermalmanagementrelateddatastreams.
Theoperationsareoutlinedasfollows:
1. CoolingCapabilityIdentification
l
ThePRxmayrequestPTx’scoolingcapabilitybysendingthedatastreammessageGET_COOLING_INFO
(Section5.2.1,GetCoolingInfo-GET_COOLING_INFO-(0x1)).
l
ThePTxshallrespondwiththedatastreammessageCOOLING_INFO(Section5.3.1,CoolingInfo-COOLING_
INFO-(0x1)).
2. CoolingLevelSelection
l
ThePRxmayselectspecificcoolinglevelbysendingthedatastreammessageSET_COOLING_PARAM
(Section5.2.2,SetCoolingParameters-SET_COOLING_PARAM-(0x2)).
l
ThePTxshallgeneratearesponsetoindicatethestatusoftheoperatio
...