ISO/IEC 14443-2:2020

INTERNATIONAL ISO/IEC
STANDARD 14443-2
Fourth edition
2020-07
Cards and security devices for
personal identification — Contactless
proximity objects —
Part 2:
Radio frequency power and signal
interface
Cartes et dispositifs de sécurité pour l'identification personnelle —
Objets sans contact de proximité —
Partie 2: Interface radiofréquence et des signaux de communication
Reference number
©
ISO/IEC 2020
© ISO/IEC 2020
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Published in Switzerland
ii © ISO/IEC 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 General considerations . 5
5.1 Initial dialogue . 5
5.2 Compliance . 5
5.2.1 PICC compliance . 5
5.2.2 PCD compliance . 5
6 Power transfer . 6
6.1 General . 6
6.2 Frequency . 6
6.3 Operating field strength . 6
7 Signal interface . 7
8 Communication signal interface Type A . 9
8.1 Communication PCD to PICC . . 9
8.1.1 Bit rate . 9
8.1.2 Modulation . 9
8.1.3 Bit representation and coding .18
8.2 Communication PICC to PCD . .23
8.2.1 Bit rate .23
8.2.2 PICC load modulation transmission .23
8.2.3 Subcarrier .27
8.2.4 Subcarrier modulation .28
8.2.5 PCD load modulation reception .28
8.2.6 Bit representation and coding .32
9 Communication signal interface Type B .32
9.1 Communication PCD to PICC . .32
9.1.1 Bit rate .32
9.1.2 Modulation for bit rates of f /128, f /64, f /32, f /16, f /8, f /4, and f /2 .33
c c c c c c c
9.1.3 Bit representation and coding .41
9.2 Communication PICC to PCD . .41
9.2.1 Bit rate .41
9.2.2 PICC load modulation transmission .42
9.2.3 Subcarrier .42
9.2.4 Subcarrier modulation .42
9.2.5 PCD load modulation reception .42
9.2.6 Bit representation and coding .42
10 Electromagnetic disturbance levels .42
10.1 PCD limits .42
10.2 PICC limits .42
Annex A (informative) Complex envelope and constellation diagram .44
Annex B (informative) Inter symbol interference .45
Bibliography .47
© ISO/IEC 2020 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that
are members of ISO or IEC participate in the development of International Standards through
technical committees established by the respective organization to deal with particular fields of
technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also
take part in the work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents) or the IEC
list of patent declarations received (see http:// patents .iec .ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 17, Cards and security devices for personal identification.
This fourth edition cancels and replaces the third edition (ISO/IEC 14443-2:2016), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— amendment of active and passive PICC transmissions;
— amendment of electromagnetic disturbance levels for all PICC classes.
A list of all parts in the ISO/IEC 14443 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO/IEC 2020 – All rights reserved

Introduction
ISO/IEC 14443 (all parts) is one of a group of International Standards describing the parameters for
identification cards as defined in ISO/IEC 7810 and the use of such cards for international interchange.
This document describes the electrical characteristics of two types of contactless interface between a
proximity card and a proximity coupling device. The interface includes both power and bi-directional
communication. It is intended to be used in conjunction with other parts of the ISO/IEC 14443 series.
Contactless card standards cover a variety of types as embodied in ISO/IEC 10536 (all parts) (close-
coupled cards), ISO/IEC 14443 (all parts) (proximity cards), and ISO/IEC 15693 (all parts) (vicinity
cards). These are intended for operation when very near, nearby and at a longer distance from
associated coupling devices, respectively.
© ISO/IEC 2020 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 14443-2:2020(E)
Cards and security devices for personal identification —
Contactless proximity objects —
Part 2:
Radio frequency power and signal interface
1 Scope
This document specifies the characteristics of the fields to be provided for power and bi-directional
communication between proximity coupling devices (PCDs) and proximity cards or objects (PICCs).
This document does not specify the means of generating coupling fields, nor the means of compliance
with electromagnetic radiation and human exposure regulations, which can vary depending on the
country.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10373-6, Cards and security devices for personal identification — Test methods — Part 6:
Contactless proximity objects
ISO/IEC 14443-1:2018, Cards and security devices for personal identification — Contactless proximity
objects — Part 1: Physical characteristics
ISO/IEC 14443-3:2018, Cards and security devices for personal identification — Contactless proximity
objects — Part 3: Initialization and anticollision
3 Terms and definitions
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
bit duration
time during which a logic level is defined, at the end of which a new bit starts
3.2
BPSK
phase shift keying where the phase shift is 180°, resulting in two phase state possibilities
3.3
modified Miller
method of bit coding whereby a logic level during a bit duration (3.1) is represented by the position of a
pulse within the bit frame
© ISO/IEC 2020 – All rights reserved 1

3.4
modulation index
m
[1 − b] / [1 + b], where b is the ratio between the modulated amplitude and the initial signal amplitude
Note 1 to entry: The value of the index may be expressed as a percentage.
3.5
NRZ-L
method of bit coding whereby a logic level during a bit duration (3.1) is represented by one of two
defined physical states of a communication medium
3.6
operating volume
positions, for each PICC class, where the corresponding Reference PICC and Active Reference PICC show
PCD compliance with all requirements of this document for this class
3.7
subcarrier
signal of frequency, f , used to modulate a carrier of frequency, f
s c
3.8
Manchester
method of bit coding whereby a logic level during a bit duration (3.1) is represented by a sequence of
two defined physical states of a communication medium, the order of the physical states within the
sequence defining the logical state
3.9
TR0
guard time between the end of a PCD transmission and the start of the PICC subcarrier (3.7) generation
3.10
TR1
synchronization time between the start of the PICC subcarrier (3.7) generation and the start of the PICC
subcarrier modulation
4 Symbols and abbreviated terms
a pulse shape factor, Type A
ACP actual constellation point
AP actual phase value
ASK amplitude shift keying
b ratio between the modulated and initial signal amplitude, Type B
BPSK binary phase shift keying
EMD electromagnetic disturbance, parasitically generated by the PICC
EPI elementary phase interval
etu elementary time unit
f frequency of operating field (carrier frequency)
c
f frequency of subcarrier
s
2 © ISO/IEC 2020 – All rights reserved

H equivalent homogenous magnetic field strength
H field strength of the unmodulated RF field
INITIAL
h envelope overshoot for bit rates of f /64, f /32, and f /16, Type A
ovs c c c
h envelope undershoot, Type B
f
h envelope overshoot, Type B
r
ISI inter symbol interference
ISI inter symbol interference angle
d
ISI inter symbol interference magnitude
m
MS1 first modulated state
MS2 second modulated state
NP nominal phase value
NRZ-L non-return to zero (L for level)
OOK on/off keying
PauseA PCD modulation pulse, Type A
Ø initial phase of the subcarrier
Ø load modulation phase
LM
Ø initial value of Ø
LM, INIT LM, MEAN
Ø load modulation interstate phase drift
LM, INTER
Ø limit of Ø for PCD reception
LM, INTER, PCD LM, INTER
Ø limit of Ø for PICC transmission
LM, INTER, PICC LM, INTER
Ø load modulation intrastate phase drift
LM, INTRA
Ø limit of Ø for PCD reception
LM, INTRA, PCD LM, INTRA
Ø limit of Ø for PICC transmission
LM, INTRA, PICC LM, INTRA
Ø interstate phase
LM, MEAN
PCD proximity coupling device
PICC proximity card or object
P complex constellation point of the maximum NP
H
P complex constellation point of the minimum NP
L
PNP previous nominal phase
PR phase range
PSK phase shift keying
© ISO/IEC 2020 – All rights reserved 3

RF radio frequency
t PauseA length
t PauseA "Low" time for a bit rate of f /128
2 c
t PauseA rise time for a bit rate of f /128
3 c
t PauseA rise time section for a bit rate of f /128
4 c
t PauseA "Low" time for bit rates of f /64, f /32, and f /16
5 c c c
t PauseA rise time for bit rates of f /64, f /32, and f /16
6 c c c
t maximum value of t for PCD transmission
6, max, PCD 6
t maximum value of t for PICC reception
6, max, PICC 6
t bit duration, Type A
b
t envelope fall time, Type B
f
t maximum fall time for PCD transmission, Type B
f, max, PCD
t maximum fall time for PICC reception, Type B
f, max, PICC
t envelope rise time, Type B
r
t maximum rise time for PCD transmission, Type B
r, max, PCD
t maximum rise time for PICC reception, Type B
r, max, PICC
t pulse position, Type A
x
US unmodulated state
V modulus of the difference between US and any MS1
|MS1-US|
V EMD limit, PCD
E, PCD
V EMD limit, PICC
E, PICC
V load modulation amplitude
LMA
V minimum limit of V for PCD reception
LMA, min, PCD LMA
V minimum limit of V for PICC transmission
LMA, min, PICC LMA
V maximum limit of V for PCD reception
LMA, max, PCD LMA
V maximum limit of V for PICC transmission
LMA, max, PICC LMA
# Number
4 © ISO/IEC 2020 – All rights reserved

5 General considerations
5.1 Initial dialogue
The initial dialogue between the PCD and the PICC shall be conducted through the following consecutive
operations:
— activation of the PICC by the RF operating field of the PCD;
— the PICC shall wait silently for a command from the PCD;
— transmission of a command by the PCD;
— transmission of a response by the PICC.
These operations shall use the RF power and signal interface specified in Clauses 6 to 10.
5.2 Compliance
5.2.1 PICC compliance
The PICC shall comply with all mandatory requirements of this document and may support optional
requirements (bit rate, class, etc.). The PICC should fulfill all the requirements of one particular class in
order to improve interoperability.
5.2.2 PCD compliance
5.2.2.1 General
The PCD shall comply with all mandatory requirements of this document and may support optional
requirements (bit rate, support of PICCs of optional classes, etc.).
The PCD
— shall support PICCs of "Class 1", "Class 2", and "Class 3",
— may optionally support PICCs of "Class 4",
— may optionally support PICCs of "Class 5", and
— may optionally support PICCs of "Class 6".
PCD requirements measured with Reference PICCs 1, 2, and 3 and Active Reference PICCs 1, 2, and 3 are
mandatory for all PCDs.
PCD requirements measured with Reference PICC 4 and Active Reference PICC 4 are only mandatory
for PCDs supporting operation with "Class 4" PICCs.
PCD requirements measured with Reference PICC 5 and Active Reference PICC 5 are only mandatory
for PCDs supporting operation with "Class 5" PICCs.
PCD requirements measured with Reference PICC 6 and Active Reference PICC 6 are only mandatory
for PCDs supporting operation with "Class 6" PICCs.
For each supported PICC class, the PCD manufacturer shall indicate the operating volume within which
the PCD fulfills all requirements of this document.
© ISO/IEC 2020 – All rights reserved 5

5.2.2.2 PCD supporting PICCs of particular class(es)
If a PCD is expected to operate with PICCs of only particular class(es), it is not mandatory for this PCD
to support PICCs of other classes. This PCD shall comply with all requirements of this document non-
specific to one class. The PCD manufacturer shall clearly state which class(es) are supported.
NOTE A PCD which does not support all mandatory classes 1, 2, and 3 is not fully compliant with this document.
It can be advertised as "supporting 'Class X' PICCs only" or "compliant with Class(es) X requirements only".
6 Power transfer
6.1 General
The PCD shall produce a high frequency alternating magnetic field. This field inductively couples to the
PICC to transfer power and is modulated for communication.
6.2 Frequency
The frequency, f , of the RF operating field shall be 13,56 MHz ± 7 kHz.
c
6.3 Operating field strength
Within the manufacturer specified operating volumes (see 3.6), the PCD shall generate a field strength
of at least H and not exceeding H under unmodulated conditions, see Table 1.
min max
The PCD
— shall support PICCs of "Class 1", "Class 2", and "Class 3",
— may optionally support PICCs of "Class 4",
— may optionally support PICCs of "Class 5", and
— may optionally support PICCs of "Class 6".
PCD requirements measured with Reference PICCs 1, 2, and 3 are mandatory for all PCDs.
PCD requirements measured with Reference PICC 4 are only mandatory for PCDs supporting operation
with "Class 4" PICCs.
PCD requirements measured with Reference PICC 5 are only mandatory for PCDs supporting operation
with "Class 5" PICCs.
PCD requirements measured with Reference PICC 6 are only mandatory for PCDs supporting operation
with "Class 6" PICCs.
Table 1 — PCD field strength
H H
min max
A/m (rms) A/m (rms)
Measured with Reference PICC 1 1,5 7,5
Measured with Reference PICC 2 1,5 8,5
Measured with Reference PICC 3 1,5 8,5
Measured with Reference PICC 4 (optional) 2,0 12
Measured with Reference PICC 5 (optional) 2,5 14
Measured with Reference PICC 6 (optional) 4,5 18
6 © ISO/IEC 2020 – All rights reserved

The PCD shall not generate a field strength higher than the average and maximum levels specified for
all mandatory and optional classes in ISO/IEC 14443-1:2018, 4.4 (alternating magnetic field) in any
possible PICC position and orientation, measured with the associated Reference PICCs.
Test methods for the PCD operating field are defined in ISO/IEC 10373-6 and use a dedicated Reference
PICC for each class.
If the PICC meets the requirements of one particular class as specified in ISO/IEC 14443-1, then the PICC
shall operate as intended continuously between H and H defined for its class, see Table 2; this
min max
includes all PICC requirements defined in this document and processing of the manufacturer specified
set of commands.
If the PICC does not claim to meet the requirements of one particular class as specified in
ISO/IEC 14443-1, then:
— if the PICC antenna fits within the external rectangle defined in "Class 2" as specified in
ISO/IEC 14443-1, then
— the PICC shall operate as intended continuously between H and H defined for "Class 2",
min max
see Table 2,
— the PICC shall pass the loading effect test defined for "Class 2";
— if the PICC antenna fits within the external rectangle or external circle defined in "Class 3" as
specified in ISO/IEC 14443-1, then
— the PICC shall operate as intended continuously between H and H defined for "Class 3",
min max
see Table 2,
— the PICC shall pass the loading effect test defined for "Class 3";
— if the PICC antenna does not claim to fit within the external rectangle or external circle defined in
"Class 2" or "Class 3" as specified in ISO/IEC 14443-1, then
— the PICC shall operate as intended continuously between H and H defined for "Class 1", see
min max
Table 2,
— the PICC shall pass the loading effect test defined for "Class 1".
NOTE 1 If the PICC does not claim to meet the requirements of one particular class, then the requirements
defined above are sufficient to guarantee proper operation and interoperability with PCDs.
Table 2 — PICC operating field strength
H H
min max
A/m (rms) A/m (rms)
"Class 1" PICC 1,5 7,5
"Class 2" PICC 1,5 8,5
"Class 3" PICC 1,5 8,5
"Class 4" PICC 2,0 12
"Class 5" PICC 2,5 14
"Class 6" PICC 4,5 18
NOTE 2 Margins of field strength are effectively included by the test methods as specified in ISO/IEC 10373-6.
7 Signal interface
In order to transmit data to the PICC, the PCD modulates the amplitude of its alternating magnetic field
strength with modulation pulses.
© ISO/IEC 2020 – All rights reserved 7

In order to transmit data to the PCD, the PICC passively loads the PCD alternating magnetic field and/or
actively contributes with its own alternating magnetic field. This is called load modulation.
Within the manufacturer specified operating volumes (see 3.6), the PCD shall generate modulation
pulses as described in Clauses 8 and 9 and shall be capable of receiving the minimum load modulation
amplitude.
NOTE 1 As an indication of the operating volume, the manufacturer can give the operating range (e.g. 0 to
X cm) within which all requirements of this document are fulfilled.
Test methods for the PCD communication signal interface are defined in ISO/IEC 10373-6.
Two communication signal interfaces, Type A and Type B, are described in Clauses 8 and 9. The PCD
shall alternate between modulation methods when idling before detecting the presence of a PICC of
Type A or Type B.
Only one communication signal interface may be active during a communication session until
deactivation by the PCD or removal of the PICC. Subsequent session(s) may then proceed with either
modulation method.
Table 3 and Table 4 illustrate the concepts described in Clauses 8 and 9.
Table 3 — Example PCD to PICC communication signals for Type A and Type B interfaces
Type A Type B
ASK ~ 100 % ASK ~ 10 %
bit rates of
modified Miller NRZ-L
f /128, f /64,
c c
f /32, and f /16
c c
ASK ~ 10 %
NRZ–L
bit rates of f /8,
c
f /4, and f /2
c c
bit rates of
3f /4, f , PSK, see 8.1.2.5.
c c
3f /2, and 2f
c c
NOTE 2 For the coding of modified Miller, see 8.1.3.1.
Table 4 — Example PICC to PCD communication signals for Type A and Type B interfaces
Type A Type B
Load modulation Load modulation
Subcarrier f /16 Subcarrier f /16
c c
OOK BPSK
bit rate of
Manchester NRZ-L
f /128
c
Load modulation
Subcarrier f /16
c
BPSK
NRZ-L
bit rate of f /64
c
8 © ISO/IEC 2020 – All rights reserved

Table 4 (continued)
Type A Type B
Load modulation
Subcarrier f /16
c
BPSK
NRZ-L
bit rate of f /32
c
Load modulation
Subcarrier equals the bit rate
BPSK
bit rates of
NRZ-L
f /16, f /8, f /4,
c c c
and f /2
c
8 Communication signal interface Type A
8.1 Communication PCD to PICC
8.1.1 Bit rate
The bit rate for the transmission during initialization and anticollision shall be f /128 (~106 kbit/s).
c
The bit rate for the transmission after initialization and anticollision shall be one of the following:
— f /128 (~106 kbit/s);
c
— f /64 (~212 kbit/s);
c
— f /32 (~424 kbit/s);
c
— f /16 (~848 kbit/s);
c
— f /8 (~1,70 Mbit/s);
c
— f /4 (~3,39 Mbit/s);
c
— f /2 (~6,78 Mbit/s);
c
— 3f /4 (~10,17 Mbit/s);
c
— f (~13,56 Mbit/s);
c
— 3f /2 (~20,34 Mbit/s);
c
— 2f (~27,12 Mbit/s).
c
8.1.2 Modulation
8.1.2.1 General
8.1.2.2 to 8.1.2.5 describe the modulation waveform requirements for all bit rates.
NOTE Filtering of the PCD modulation is defined in ISO/IEC 10373-6. Some extreme values can be filtered
out. This can affect the relevant timing parameter associated with the fall and rise timings as well as overshoot
and undershoot values.
© ISO/IEC 2020 – All rights reserved 9

8.1.2.2 Modulation for a bit rate of f /128
c
Communication from PCD to PICC for a bit rate of f /128 shall use the modulation principle of ASK 100 %
c
of the RF operating field to create a PauseA as shown in Figure 1.
The envelope of the PCD field shall decrease monotonically to less than 5 % of its initial value H
INITIAL
and remain less than 5 % for t . This envelope shall comply with Figure 1.
If the envelope of the PCD field does not decrease monotonically, the time between a local maximum
and the time of passing the same value before the local maximum shall not exceed 0,5 μs. This shall only
apply if the local maximum is greater than 5 % of H .
INITIAL
The PauseA length t is the time between 90 % of the falling edge and 5 % of the rising edge of the
H-field signal envelope.
In case of an overshoot, the field shall remain within 90 % of H and 110 % of H .
INITIAL INITIAL
Key
1 start of t
2 end of t
3 end of t
4 start of t
5 end of t and t , start of t and t
1 2 3 4
Figure 1 — PauseA for a bit rate of f /128
c
The PCD shall generate a PauseA with timing parameters defined in Table 5.
Table 5 — PCD transmission: PauseA timing parameters for a bit rate of f /128
c
Parameter Condition Minimum Maximum
t 28/f 40,5/f
1 c c
t > 34/f 7/f
1 c c
t t
2 1
t ≤ 34/f 10/f
1 c c
t 1,5 × t 16/f
3 4 c
t 0 6/f
4 c
10 © ISO/IEC 2020 – All rights reserved

PCD implementations may be restricted to generate a PauseA with values of t = n/f (n = integer).
1 c
Therefore, measurement of t should be rounded to the closest n in the unit 1/f .
1 c
NOTE 1 The maximum value of t is a function of the measured value of t .
2 1
NOTE 2 The minimum value of t is a function of the measured value of t .
3 4
The PICC shall be able to receive a PauseA with timing parameters defined in Table 6.
Table 6 — PICC reception: PauseA timing parameters for a bit rate of f /128
c
Parameter Condition Minimum Maximum
t 27,5/f 41/f
1 c c
t > 34/f 6/f
1 c c
t t
2 1
t ≤ 34/f 9/f
1 c c
t 1,5 × t 17/f
3 4 c
t 0 7/f
4 c
NOTE 3 The maximum value of t is a function of the set value of t .
2 1
NOTE 4 The minimum value of t is a function of the set value of t .
3 4
For a bit rate of f /128, the PCD shall generate a PauseA with a rise time t
c 3
— greater than both 0/f and (t − t ) − 24,5/f , and
c 1 2 c
— less than both (t − t ) + 7/f and 16/f .
1 2 c c
For a bit rate of f /128, the PICC shall be able to receive a PauseA with a rise time t
c 3
— greater than both 0/f and (t − t ) − 26/f , and
c 1 2 c
— less than both (t − t ) + 8/f and 17/f .
1 2 c c
NOTE 5 Minimum and maximum values of (t − t ) are derived from minimum and maximum values of t and
1 2 1
t defined in Table 5 and Table 6.
The timing parameters for PCD and PICC are illustrated in Figure 2.
Figure 2 — PauseA timing parameters for a bit rate of f /128
c
© ISO/IEC 2020 – All rights reserved 11

8.1.2.3 Modulation for bit rates of f /64, f /32, and f /16
c c c
Communication from PCD to PICC for bit rates of f /64 (~212 kbit/s), f /32 (~424 kbit/s), and f /16
c c c
(~848 kbit/s) shall use the modulation principle of ASK (with different values for "a") of the operating
field strength to create a PauseA as shown in Figure 3.
Key
1 start of t
2 end of t
3 start of t
4 end of t and t , start of t
1 5 6
Figure 3 — PauseA for bit rates of f /64, f /32, and f /16
c c c
The envelope of the PCD field shall decrease monotonically to the maximum value of parameter "a" as
defined in Table 7. Then, if the envelope evolution becomes non-monotonic, the difference between any
local maximum and the lowest previous minimum (within the same PauseA) shall not exceed 0,09 times
the difference between the initial amplitude and the previous lowest minimum.
The parameter "a" is the lowest minimum within PauseA.
In case of an overshoot, the field shall remain within H × (1 − h ) and H × (1 + h ).
INITIAL ovs INITIAL ovs
The PCD shall generate a PauseA with timing and amplitude parameters defined in Table 7.
Table 7 — PCD transmission: PauseA parameters for bit rates of f /64, f /32, and f /16
c c c
Parameter Bit rate Minimum Maximum
f /64 0 0,18
c
a f /32 0 0,38
c
f /16 0,22 0,58
c
f /64 16,5/f 20/f
c c c
t f /32 8,0/f 10/f
1 c c c
f /16 4,0/f 5/f
c c c
12 © ISO/IEC 2020 – All rights reserved

Table 7 (continued)
Parameter Bit rate Minimum Maximum
f /64 t /2 + 4/f t
c 1 c 1
t f /32 t /2 + 1/f t
5 c 1 c 1
f /16 t /2 t
c 1 1
f /64 See requirements above Figure 4
c
t f /32 See requirements above Figure 5
6 c
f /16 See requirements above Figure 6
c
f /64, f /32, and
c c
h 0 [1 − t / (2 × t )] × 0,10 × (1 − a)
ovs 6 6, max, PCD
f /16
c
NOTE 1 The minimum and maximum values of t are functions of the measured value of t .
5 1
NOTE 2 The maximum value of h for PCD transmission is a function of the measured value of t and of
OVS 6
t (see requirements above Figure 4, Figure 5, or Figure 6).
6, max, PCD
PCD implementations may be restricted to generate a PauseA with values of t = n/f (n = integer).
1 c
Therefore, measurement of t should be rounded to the closest n in the unit 1/f .
1 c
The PICC shall be able to receive a PauseA with timing and amplitude parameters defined in Table 8.
Table 8 — PICC reception: PauseA parameters for bit rates of f /64, f /32, and f /16
c c c
Parameter Bit rate Min Max
f /64 0 0,2
c
a f /32 0 0,4
c
f /16 0,2 0,6
c
f /64 16/f 20/f
c c c
t f /32 8/f 10/f
1 c c c
f /16 4/f 5/f
c c c
f /64 t /2 + 3/f t
c 1 c 1
t f /32 t /2 + 1/f t
5 c 1 c 1
f /16 t /2 t
c 1 1
f /64 See requirements above Figure 4
c
t f /32 See requirements above Figure 5
6 c
f /16 See requirements above Figure 6
c
f /64, f /32, and
c c
h 0 [1 − t / (2 × t )] × 0,11 × (1 − a)
ovs 6 6, max, PICC
f /16
c
NOTE 3 The minimum and maximum values of t are functions of the set value of t .
5 1
NOTE 4 The maximum value of h for PICC reception is a function of the set value of t and of t (see
OVS 6 6, max, PICC
requirements above Figure 4, Figure 5, or Figure 6).
NOTE 5 The PauseA length t is the time between an envelope amplitude of [a + 0,9 × (1 − a)] on the falling
edge and [a + 0,1 × (1 − a)] on the rising edge.
For a bit rate of f /64, the PCD shall generate a PauseA with a rise time t
c 6
— greater than both 0/f and (t − t ) − 3/f , and
c 1 5 c
— less than both (t − t ) + 8/f and t = 11/f .
1 5 c 6, max, PCD c
For a bit rate of f /64, the PICC shall be able to receive a PauseA with a rise time t
c 6
— greater than both 0/f and (t − t ) − 4/f , and
c 1 5 c
© ISO/IEC 2020 – All rights reserved 13

— less than both (t − t ) + 9/f and t = 12/f .
1 5 c 6, max, PICC c
NOTE 6 Minimum and maximum values of (t − t ) are derived from minimum and maximum values of t and
1 5 1
t defined in Table 7 and Table 8.
The timing parameters for PCD and PICC are illustrated in Figure 4.
Figure 4 — PauseA timing parameters for a bit rate of f /64
c
For a bit rate of f /32, the PCD shall generate a PauseA with a rise time t
c 6
— greater than 0/f , and
c
— less than both (t − t ) + 8/f and t = 9/f .
1 5 c 6, max, PCD c
For a bit rate of f /32, the PICC shall be able to receive a PauseA with a rise time t
c 6
— greater than 0/f , and
c
— less than both (t − t ) + 8/f and t = 10/f .
1 5 c 6, max, PICC c
The timing parameters for PCD and PICC are illustrated in Figure 5.
NOTE 7 Minimum and maximum values of (t − t ) are derived from minimum and maximum values of t and
1 5 1
t defined in Table 7 and Table 8.
14 © ISO/IEC 2020 – All rights reserved

Figure 5 — PauseA timing parameters for a bit rate of f /32
c
For a bit rate of f /16, the PCD shall generate a PauseA with a rise time t
c 6
— greater than 0/f , and
c
— less than both (t − t ) + 4/f and t = 5,5/f .
1 5 c 6, max, PCD c
For a bit rate of f /16 the PICC shall be able to receive a PauseA with a rise time t
c 6
— greater than 0/f , and
c
— less than both (t − t ) + 4,5/f and t = 6/f .
1 5 c 6, max, PICC c
NOTE 8 Minimum and maximum values of (t − t ) are derived from minimum and maximum values of t and
1 5 1
t defined in Table 7 and Table 8.
The timing parameters for PCD and PICC are illustrated in Figure 6.
Figure 6 — PauseA timing parameters for a bit rate of f /16
c
© ISO/IEC 2020 – All rights reserved 15

8.1.2.4 Modulation for bit rates of f /8, f /4, and f /2
c c c
See 9.1.2.
8.1.2.5 Modulation for bit rates of 3f /4, f , 3f /2, and 2f
c c c c
For communication from PCD to PICC using bit rates of 3f /4, f , 3f /2, and 2f , information is encoded by
c c c c
PSK modulation of RF carrier of the operating field.
For bit rates of 3f /4, f , 3f /2, and 2f , information is encoded by PSK modulation of the RF carrier. The
c c c c
RF carrier is phase modulated with an NP at each etu. For each bit rate, the length of an etu and the
number of NPs are specified in Table 9.
Table 9 — etu and number of NPs
Bit rate etu number of NPs
3f /4 (~10,17 Mbit/s) 4/f 8
c c
f (~13,56 Mbit/s) 4/f 16
c c
3f /2 (~20,34 Mbit/s) 2/f 8
c c
2f (~27,12 Mbit/s) 2/f 16
c c
The difference between two consecutive NPs is defined as EPI, specified in Table 10 and illustrated in
Figure 7.
Key
X real
Y imaginary
nominal constellation point
R the signal amplitude
Figure 7 — Nominal constellation points
Table 10 — EPI
Bit rate EPI
3f /4 (~10,17 Mbit/s) 8°
c
f (~13,56 Mbit/s) 4°
c
3f /2 (~20,34 Mbit/s) 8°
c
2f (~27,12 Mbit/s) 4°
c
16 © ISO/IEC 2020 – All rights reserved

The difference between the angle of P and the angle of P defines the phase range PR as illustrated in
H L
Figure 7. The PCD and PICC shall respect the PR limits as specified in Table 11 and Table 12.
Table 11 — PR for PCD transmission
Bit rate Minimum PR Maximum PR
3f /4, 3f /2 54° 58°
c c
f , 2f 58° 62°
c c
Table 12 — PR for PICC reception
Bit rate Minimum PR Maximum PR
3f /4, 3f /2 52° 60°
c c
f , 2f 56° 64°
c c
Due to the limited bandwidth channel, the intended nominal phase modulation is affected by inter
symbol interference (ISI) resulting in an ACP at the end of each etu. The angle of the ACP is defined as
AP. This is described in a constellation diagram with ISI and ISI as specified below in Table 13 and
m d
Table 14 and illustrated in Figure 8.
Key
X real
Y imaginary
nominal constellation point
actual constellation point
Figure 8 — Actual constellation points
NOTE See Annex A for explanation on constellation diagrams. See Annex B for explanation on ISI.
L The maximum distance of any two ACPs related to the same NP.
ISI The rotation of all ACPs modulations related to one NP. It is defined as the angle between the line
d
through P , P and the line through any 2 ACPs with maximum distance related to the same NP.
H L
ISI The ISI magnitude normalized to the EPI. ISI = arcsin(L/R)/EPI. The PCD and PICC shall respect
m m
ISI limits for all ACPs as a function of ISI as specified in Table 13 and Table 14, and illustrated in
m d
Figure 9.
© ISO/IEC 2020 – All rights reserved 17

Table 13 — ISI limits for PCD transmission
m
Condition Minimum Maximum
abs(ISI ) ≤ 90° 0 1,5 − abs(ISI )/90°
d d
ISI
m
abs(ISI ) > 90° 0 0,5
d
Table 14 — ISI limits for PICC reception
m
Condition Minimum Maximum
abs(ISI ) ≤ 90° 0 1,6 − abs(ISI )/90°
d d
ISI
m
abs(ISI ) > 90° 0 0,6
d
Key
X ISI [°]
d
Y ISI [EPI]
m
Figure 9 — Maximum ISI limits for PCD and PICC
m
APs may vary randomly due to phase noise. The instantaneous phase error caused by noise is defined as
the difference between the AP and the NP of 0° of an unmodulated signal sampled at the end of each etu.
The differential phase error is defined as the difference of two consecutive instantaneous phase errors.
The normalized differential phase noise is the rms value of the differential phase error divided by EPI.
The normalized differential phase noise shall be lower than 0,033 for PCD transmission and lower than
0,035 for PICC reception.
8.1.3 Bit representation and coding
8.1.3.1 Bit representation and coding for bit rates of f /128, f /64, f /32, and f /16
c c c c
The following sequences are defined:
— sequence X: after a time of half the bit duration (t ), a PauseA shall occur;
x
— sequence Y: for the full bit duration (t ), no modulation shall occur;
b
— sequence Z: at the beginning of the bit duration (t ), a PauseA shall occur.
b
Figure 10, together with the timing parameters in Table 15, illustrates sequences X, Y, and Z.
18 © ISO/IEC 2020 – All rights reserved

a) Sequence X b) Sequence Y c) Sequence Z
Key
0 modulation
1 no modulation
Figure 10 — Sequences for Type A communication PCD to PICC (logical modulation signal)
Table 15 — Parameters for sequences
Bit rate
Parameter
f /128 f /64 f /32 f /16
c c c c
t 128/f 64/f 32/f 16/f
b c c c c
t 64/f 32/f 16/f 8/f
x c c c c
t see t of Table 5 see t of Table 7
1 1 1
The above sequences shall be used to code the following information:
— logic "1": sequence X;
— logic "0": sequence Y with the following two exceptions:
i) if there are two or more contiguous "0"s, sequence Z shall be used
from the second "0" on;
ii) if the first bit after a "start of communication" is "0", sequence Z
shall be used to represent this and any "0"s which follow directly
thereafter.
— start of communication: sequence Z;
— end of communication: logic "0" followed by sequence Y;
— no information: at least two sequences Y.
8.1.3.2 Bit representation and coding for bit rates of f /8, f /4, and f /2
c c c
Bit representation and coding is defined in 9.1.3.
Start of communication shall be as defined in ISO/IEC 14443-3:2018, 7.1.4.
End of communication shall be as defined in ISO/IEC 14443-3:2018, 7.1.5.
8.1.3.3 Bit representation and coding for bit rates of 3f /4 and 3f /2
c c
For start of communication, the PCD shall generate a sequence of 140 NPs starting with NP of etu #1 as
spe
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