oSIST prEN IEC 63758-10:2026

• 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 63758-10:2026 - Qi Specification - Version 2.3 - Part 10: Communications physical layer (Fast Track)

oSIST prEN IEC 63758-10:2026 is the Slovenian standard published by SIST for the Qi Specification - Version 2.3 - Part 10: Communications physical layer (Fast Track). It specifies the low-level communications used in Qi wireless power systems, including load modulation from the Power Receiver to the Power Transmitter and frequency-shift keying from the Power Transmitter to the Power Receiver. Engineers, product teams, and test labs use it to build, decode, and verify Qi communication behavior.

What does oSIST prEN IEC 63758-10:2026 specify?

oSIST prEN IEC 63758-10:2026 defines the physical layer and data link layer formats for Qi communications. It covers data bits, data bytes, and data packets, and it also gives requirements and guidance for load modulation and frequency-shift keying.

The document is organized into three main clauses:

Clause	What it covers
1. General	Structure of the Qi Specification, scope, compliance language, references, and conventions
2. Load Modulation	Power Receiver to Power Transmitter communications
3. Frequency-shift keying	Power Transmitter to Power Receiver communications and response patterns

In practice, this means the standard tells implementers how Qi communication is framed, encoded, and checked in both directions.

What are the key requirements of oSIST prEN IEC 63758-10:2026?

The most important requirements are in Clause 1 for notation and in Clauses 2 and 3 for the two communication directions. The standard is focused on signal encoding, packet framing, and error detection, so these are the points that matter most when designing hardware or testing interoperability.

General rules and conventions

Clause 1 sets the rules for reading the document. Mandatory statements use words such as “shall,” while recommendations, permissions, and capabilities use different verbal forms. The document also says that numeric values are exact unless a tolerance is stated.

It also defines how packet fields are stored and read. Multi-byte numeric fields use big-endian order, text strings use printable ASCII characters, and shorthand packet names combine a mnemonic with a modifier. For implementers, this matters because the same packet will only be interpreted correctly if byte order, text encoding, and naming conventions are handled exactly as defined.

Load modulation: Power Receiver to Power Transmitter

Clause 2 defines how the Power Receiver communicates back to the Power Transmitter by changing the amount of power it draws from the Power Signal. The Power Transmitter detects that change as a modulation of current and/or voltage on the Primary Cell.

The Power Receiver uses two amplitude states, HI and LO, and the transition between them is constrained so the transmitter can detect it reliably. In practical terms, the receiver design has to create a visible and repeatable change in load without breaking normal power transfer. The clause also ties proper operation to alignment and loading conditions, so product design has to work over the intended mechanical and electrical operating range.

Bit, byte, and packet encoding for load modulation

Clause 2 uses differential bi-phase encoding for data bits. A ONE is sent with two transitions, and a ZERO with one transition. The byte format is asynchronous serial and includes a start bit, 8 data bits, a parity bit, and a stop bit, with odd parity for this direction.

The packet structure is preamble, header, message, and checksum. The header identifies the packet type and also determines message length, the message must match the packet type, and the checksum must be consistent with the header and message bytes. For readers, the practical point is that a packet is valid only if bit timing, parity, packet type, and checksum all agree; otherwise the receiver or transmitter must discard it.

Frequency-shift keying: Power Transmitter to Power Receiver

Clause 3 defines the opposite direction, where the Power Transmitter uses Frequency Shift Keying (FSK) by changing the Operating Frequency of the Power Signal. The modulation is controlled by polarity and depth, so configuration has to match the expected parameter set.

This clause also uses differential bi-phase bit encoding, but with even parity for the byte format. It requires contiguous transmission of bits and bytes, with no pauses between them. In practice, decoders need to tolerate the permitted timing variation while still rejecting malformed packets.

Response handling

Clause 3 also defines Response Patterns for simple query data packets. The four possible responses are ACK, NAK, ND, and ATN.

This is important for simple, low-overhead communication handling. Instead of a full byte-framed response, the receiver can identify one of the fixed response patterns directly.

What terms does oSIST prEN IEC 63758-10:2026 define?

• Wireless Power Consortium (WPC) - The organization named in the document as the body promoting global wireless power standards.
• Power Receiver - The device that draws power from the Power Signal and sends load-modulated communication back to the Power Transmitter.
• Power Transmitter - The device that supplies the Power Signal and sends FSK communication to the Power Receiver.
• Primary Cell - The transmitter-side electrical path whose current and voltage are monitored during load modulation.
• Operating Frequency - The frequency of the Power Signal that the Power Transmitter shifts during FSK.
• Frequency-shift keying (FSK) - The transmit method where the Power Transmitter switches between two operating frequencies to encode data.
• Response Pattern - One of the fixed 8-bit reply patterns used after a simple query, with the named forms ACK, NAK, ND, and ATN.

Who uses oSIST prEN IEC 63758-10:2026?

This standard is used by teams building Qi wireless power products and the tools that verify them. It is relevant where interoperability depends on exact signal timing and packet handling.

Typical users include:

• Hardware and firmware engineers designing Qi Power Receivers and Power Transmitters
• ASIC and embedded software teams implementing bit encoding, packet framing, and checksum handling
• Test laboratories checking decoding, packet validity, parity, and response behavior
• Quality and compliance teams verifying that Qi communications behave as specified
• Product teams working on flat-surface devices such as mobile phones and chargers, especially the application area noted in the document

Which standards are used with oSIST prEN IEC 63758-10:2026?

• ISO/IEC Directives, Part 2 - Provides the wording rules used for requirements, recommendations, permissions, and capabilities.
• Qi Specification, Communications Protocol - Defines the packet mnemonics, packet classifications, and message content referenced by this part.
• Qi Specification, Power Delivery - Provides the odd-parity convention noted for Power Receiver to Power Transmitter communications.

What does the oSIST prEN IEC 63758-10:2026 document contain?

The document contains the rules for Qi physical-layer communication, plus the figures and tables needed to implement and test it. It includes a general section on notation and compliance, then separate sections for load modulation and FSK.

It shows packet structures, bit encodings, byte encodings, and start/end timing diagrams for data packets. It also includes tables for message-size calculation, modulation timing, FSK state parameters, receiver tolerance to cycle variation, and response patterns.

For implementation work, these contents are used to build encoders and decoders. For testing and validation, they define what counts as a correct packet, a correct checksum, and a valid response.

SLOVENSKI STANDARD
01-november-2026
Specifikacija Qi - Različica 2.3 - 10. del: Fizična raven komunikacije (hitri
postopek)
Qi Specification - Version 2.3 - Part 10: Communications physical layer (Fast Track)
Ta slovenski standard je istoveten z: prEN IEC 63758-10:2026
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.

100/4553/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 63758-10 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 10: Communications physical layer (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
CommunicationsPhysicalLayer
Version2.3
PublishDate:08December2025
DISCLAIMER
The information contained herein is believed to be accurate as of the date of publication, but is provided “as is” and may
contain errors. The Wireless Power Consortium makes no warranty, express or implied, with respect to this document
and its contents, including any warranty of title, ownership, merchantability, or fitness for a particular use or purpose.
Neither the Wireless Power Consortium, nor any member of the Wireless Power Consortium will be liable for errors in
this document or for any damages, including indirect or consequential, from use of or reliance on the accuracy of this
document. For any further explanation of the contents of this document, or in case of any perceived inconsistency or
ambiguity of interpretation, 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. LoadModulation 8
2.1 Modulationscheme 8
2.2 Bitencodingscheme 9
2.3 Byteencodingscheme 10
2.4 Datapacketstructure 10
2.4.1 Header 11
2.4.2 Message 11
2.4.3 Checksum 11
2.4.4 Correctreceptionofadatapacket 12
2.4.5 Startandendofadatapacket 12
3. Frequency-shiftkeying 13
3.1 Modulationscheme 13
3.2 Bitencodingscheme 14
3.3 Byteencodingscheme 15
3.4 Datapacketstructure 16
3.4.1 Header 16
3.4.2 Message 17
3.4.3 Checksum 17
3.4.4 Correctreceptionofadatapacket 17
3.4.5 Startandendofadatapacket 17
3.5 ResponsePattern 18
1. General
The Wireless Power Consortium (WPC) is a worldwide organization that aims to develop and promote global standards
for wireless power transfer in various application areas. An important application area comprises flat-surface devices
such as mobile phones and chargers operating at power levels up to 25 W.
1.1 StructureoftheQi Specification
Generaldocuments
l
Introduction
l
Glossary, Acronyms, and Symbols
l
Technical System Overview
l
Power Profiles
Systemdescriptiondocuments
l
Mechanical, Thermal, and User Interface
l
Power Delivery
l
Communications Physical Layer
l
Communications Protocol
l
Foreign Object Detection
l
NFC Tag Protection
l
Authentication Protocol
l
MPP Communications Protocol
l
MPP Magnetics Design
l
MPP Power Delivery
l
MPP Communications Physical Layer
l
MPP Foreign Object Detection
l
MPP Design Guidelines (Informative)
l
Magnetic Covers
l
Active Alignment System
l
Thermal Management Protocol
1.2 Scope
TheQiSpecification,CommunicationsPhysicalLayer (this document) defines the low-level (physical layer and the data
link layer) formats of data bits, data bytes, and data packets. In addition, it provides requirements and guidelines for
load modulation and frequency-shift keying.
1.3 Compliance
All provisions in theQiSpecification are mandatory, unless specifically indicated as recommended, optional, note,
example, or informative. Verbal expression of provisions in this Specification follow the rules provided in ISO/IEC
Directives, Part 2.
Table1-Verbalformsforexpressionsofprovisions
Provision Verbalform
requirement “shall” or “shall not”
recommendation “should” or “should not”
permission “may” or “may not”
capability “can” or “cannot”
1.4 References
For undated references, the most recently published document applies. The most recent WPC publications can be
downloaded from http://www.wirelesspowerconsortium.com.

1.5 Conventions
1.5.1 Notationofnumbers
l
Real numbers use the digits 0 to 9, a decimal point, and optionally an exponential part.
l
Integer numbers in decimal notation use the digits 0 to 9.
l
Integer numbers in hexadecimal notation use the hexadecimal digits 0 to 9 and A to F, and are prefixed by "0x"
unless explicitly indicated otherwise.
l
Single bit values use the words ZERO and ONE.
1.5.2 Tolerances
Unless indicated otherwise, all numeric values in theQiSpecification are exactly as specified and do not have any
implied tolerance.
1.5.3 Fieldsinadatapacket
A numeric value stored in a field of a data packet uses a big-endian format. Bits that are more significant are stored at a
lower byte offset than bits that are less significant. Table 2 and Figure 1 provide examples of the interpretation of such
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
Text strings consist of a sequence of printable ASCII characters (i.e. in the range of 0x20 to 0x7E) enclosed in double
quotes ("). Text strings are stored in fields of data structures with the first character of the string at the lowest byte
offset, and are padded with ASCII NUL (0x00) characters to the end of the field where necessary.
EXAMPLE: The text string “WPC” is stored in a six-byte fields as the sequence of characters 'W', 'P', 'C', NUL, NUL, and
NUL. The text string “M:4D3A” is stored in a six-byte field as the sequence 'M', ':', '4', 'D', '3', and 'A'.
1.5.5 Short-handnotationfordatapackets
In many instances, theQiSpecification refers to a data packet using the following shorthand notation:
/
In this notation, refers to the data packet's mnemonic defined in theQiSpecification,Communications
Protocol, and refers to a particular value in a field of the data packet. The definitions of the data packets in
theQiSpecification,CommunicationsProtocol, list the meanings of the modifiers.
For example, EPT/cc refers to an End Power Transfer data packet having its End Power Transfer code field set to 0x01.

2. LoadModulation
This section defines both the physical layer and the data link layer of the Power Receiver to Power Transmitter
communications interface.
The Power Receiver communicates to the Power Transmitter using backscatter modulation. For this purpose, the Power
Receiver modulates the amount of power that it draws from the Power Signal. The Power Transmitter detects this as a
modulation of the current through and/or voltage across the Primary Cell. In other words, the Power Receiver and
Power Transmitter use an amplitude modulated Power Signal to provide a Power Receiver to Power Transmitter
communications channel.
2.1 Modulationscheme
The Power Receiver shall modulate the amount of power that it draws from the Power Signal, such that the Primary Cell
(i)
current and/or Primary Cell voltage assume two states, namely a HI state and a LO state. A state is characterized in
that the amplitude is constant within a certain variation for at least ms. If the Power Receiver is properly aligned
to the Primary Cell of a type A10 or MP-A1 Power Transmitter, and for all appropriate loads, at least one of the
(ii)
following three conditions shall apply:
l
The difference of the amplitude of the Primary Cell current in the HI and LO state is at least 15 mA.
l
The difference of the Primary Cell current in the HI and LO state is at least 15 mA. The Primary Cell current is
measured at instants in time that correspond to one quarter of the cycle of the control signal driving the half-
(iii)
bridge inverter.
l
The difference of the amplitude of the Primary Cell voltage in the HI and LO state is at least 200 mV.
During a transition, the Primary Cell current and Primary Cell voltage are undefined. See Figure 2 and Table 3.
tS tS
tT
tT
t
S
HI state HI state tS
LO state LO state
Modulation
Δ
depth
Δ
100%
Figure2-AmplitudemodulationofthePowerSignal
(i)
The HI and LO states do not correspond to fixed Primary Cell current and/or Primary Cell voltage levels.
(ii)
The design requirements of the Mobile Device determine both the range of lateral displacements that constitute
proper alignment and the range of loading conditions on its Power Receiver.
(iii)
The start of the cycle corresponds the closing of the top switch in the half-bridge inverter.
Primary Cell current
Primary Cell voltage
Table3-AmplitudemodulationofthePowerSignal
Parameter Symbol Value Unit
Maximum transition time 100 μs
Minimum stable time 150 μs
Current amplitude variation 8 mA
Voltage amplitude variation 110 mV
2.2 Bitencodingscheme
The Power Receiver shall use a differential bi-phase encoding scheme to modulate data bits onto the Power Signal. For
this purpose, the Power Receiver shall align each data bit to a full period of an internal clock signal, such that the
start of a data bit coincides with the rising edge of the clock signal. This internal clock signal shall have a frequency
= (2 ± 4%) kHz.
NOTE: A ripple on the Power Receiver’s load yields a ripple on the Power Transmitter’s current. As a result, such a ripple can lead to
bit errors in the Power Transmitter. The number of bit errors can be particularly high if this ripple has a frequency that is
close to the modulation frequency .
The Receiver shall encode a ONE bit using two transitions in the Power Signal, such that the first transition coincides
with the rising edge of the clock signal and the second transition coincides with the falling edge of the clock signal. The
Receiver shall encode a ZERO bit using a single transition in the Power Signal, which coincides with the rising edge of
the clock signal.
t
CLK
ONE ZERO ONE ZERO ONE ONE ZERO ZERO
Figure3-Exampleofadifferentialbi-phaseencodingscheme

2.3 Byteencodingscheme
The Power Receiver shall use an 11-bit asynchronous serial format to transmit a data byte. This format consists of a
start bit, the 8 data bits of the byte, a parity bit, and a single stop bit. The start bit is a ZERO. The order of the data bits
is LSB first. The parity bit is odd. This means that the Power Receiver shall set the parity bit to ONE if the data byte
contains an even number of ONE bits. Otherwise, the Power Receiver shall set the parity bit to ZERO. The stop bit is a
ONE. Figure 4 shows the data byte format—including the differential bi-phase encoding of each individual bit—using the
value 0x35 as an example.
Start b0 b1 b2 b3 b4 b5 b6 b7 Parity Stop
Figure4-Exampleoftheasynchronousserialformat
2.4 Datapacketstructure
The
...