PHILIPS HTCM400/EAE

INTEGRATED CIRCUITS
DATA SHEET
HTCM400
HITAG core module hardware
Product specification
Supersedes data of 1999 Jan 01
File under Integrated Circuits, IC11
2001 Oct 04
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
CONTENTS
1
FEATURES
2
APPLICATIONS
3
GENERAL DESCRIPTION
4
ORDERING INFORMATION
5
BLOCK DIAGRAM
6
PINNING
7
FUNCTIONAL DESCRIPTION
7.1
7.1.1
7.1.2
7.1.3
7.1.4
7.1.5
7.2
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.3.5
7.3.6
7.3.7
System overview
Transponders
Host system
I/O functions
Connecting the antenna
Behaviour with several transponders
Core module software
Core module hardware
EEPROM
Microcontroller
Interface: microcontroller - host
Transmitter and receiver
Antenna
HITAG long range reader module
Interface: microcontroller - HITAG long range
board
Postal approval
Common mode filtering
Filtering of the supply voltages
Filtering of the antenna circuit
ESD protection
Security considerations
Data reliability
CRC of a data stream between reader module
and transponder
Checking user data
Data privacy
Operating security
Anticollision mode
Monitoring the supply voltage
Antenna rupture or short-circuit
7.4
7.4.1
7.4.2
7.4.3
7.4.4
7.5
7.6
7.6.1
7.6.2
7.6.3
7.7
7.7.1
7.7.2
7.7.3
2001 Oct 04
8
ELECTRICAL SPECIFICATIONS
9
MECHANICAL SPECIFICATIONS
9.1
9.2
Mounting the module
Dimensions
10
APPLICATION INFORMATION
10.1
10.2
10.3
10.3.1
Metallic environment, interferences
Distance between two antennas
To build a proximity reader
Connection of the HTCM400 in order to build a
proximity read and write device.
Power supply
Interface driver
I/O functions
To build a long range reader
Possible sources of errors by connecting the
HTCM400
10.3.2
10.3.3
10.3.4
10.4
10.5
2
11
INSTRUCTIONS FOR BUILDING HITAG
PROXIMITY ANTENNAS
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
Basics
Antenna coil
Measuring the inductance
Antenna cable length
Antenna tuning
Determining the serial resistance of the
antenna
Checking the antenna voltage VL
Procedure for practical antenna design
Reference antennas
12
SURVEY OF REFERENCED DOCUMENTS
13
DATA SHEET STATUS
14
DEFINITIONS
15
DISCLAIMERS
Philips Semiconductors
Product specification
HITAG core module hardware
1
HTCM400
FEATURES
• Compact size
• Communication with all HITAG transponders and
various other 125 kHZ transponders
• Data encryption, key handling
Nevertheless, the proximity application also prevents any
type of malfunction even if several transponders arrive in
the communication field of the antenna at the same time.
• Fast and easy system integration
• Serial CMOS interface
• Meets all requirements for CE and EMI approval.
The HITAG product family is used both in the proximity
area (operating range up to approximately 200 mm) and in
the long range area (operating range to approximately
1000 mm).
2
In both cases the HITAG core module forms the central
part as illustrated in Figs 9 and 11.
• Simple antenna design
• 5 V power supply voltage
APPLICATIONS
• HITAG proximity readers
The HITAG core module provides you with a universal,
cost-effective and small module. The use of modular
architecture guarantees versatile usability and easy
integration into bigger systems. The HITAG core module
enables communication with HITAG 1 and HITAG 2
transponders.
• HITAG long range readers.
3
GENERAL DESCRIPTION
HITAG(1) is the name of one of the universal and powerful
product lines of our 125 kHz family. The contactless
read/write system that works with passive transponders is
suitable for various applications. Inductive coupling helps
you to achieve operating distances up to 1000 mm and the
use of cryptography guarantees highest data security.
Easy integration and application of the HITAG core
module is due to:
• Small size
• Uncomplicated interfaces.
Based on the core module delivered by Philips and using
only a few additional components, every client can build
his individually designed proximity reader without difficulty.
Moreover, you can obtain the long range reader module
HTRM800 (with an additional high frequency component)
from Philips, if long range applications are required.
Anticollision mode, which is used only in long range
operation, allows you to handle several transponders that
are within the communication field of the antenna at the
same time, thus achieving highest operating security and
permitting to handle several data transfers quickly and
simultaneously. In this context anticollision becomes an
essential element of applications such as ski-ticketing and
long range access control. With applications of that type it
will always happen that several transponders arrive in the
communication field of the antenna at the same time.
(1) HITAG - is a trademark of Philips Semiconductors
Gratkorn GmbH.
4
ORDERING INFORMATION
PART NUMBER
HTCM400/EAE
2001 Oct 04
NAME
HITAG core module
3
ORDER CODE (12NC)
9352 339 00122
Philips Semiconductors
Product specification
HITAG core module hardware
5
HTCM400
BLOCK DIAGRAM
handbook, full pagewidth
power
supply
EEPROM
MEMORY
R1
antenna
TRANSMITTER
C
I/O functions
MICROCONTROLLER
R2 (1)
RECEIVER
L
CORE MODULE
HTCM400
host
system
MGW329
(1) R2 has only to be used for antenna cable lengths of more than 500 mm.
Fig.1 Block diagram.
6
PINNING
PIN
TYPE(1)
TXDEN
1
O
control pin providing connection to an RS485 interface; note 2
RXLOW_DSP
2
I
interface to the HITAG long range board
RXHIGH_DSP
3
I
SYMBOL
FUNCTION
RXCOL_DSP
4
I
TXµPL_DSP
5
O
SCLK_DSP
6
I
SFFT_DSP
7
O
i.c.
8
−
internally connected; this pin must not be connected
ACNMAN_DSP
9
O
interface to the HITAG long range board
HINMIRO_DSP
10
O
RxD
11
I
serial interface input from host; note 2
TxD
12
O
serial interface output to host; note 2
i.c.
13
−
internally connected; this pin must not be connected
i.c.
14
−
internally connected; this pin must not be connected
OUT1
15
O
OUT2
16
O
output pins of the microcontroller for controlling e.g. a LED
(connection of e.g. a BS170 or BSS123 as driver); note 2
IN1
17
I
IN2
18
I
input pins for optional switch; must be active LOW; maximum input
voltage 5 V; internal pull-up resistors are provided; note 2
DVDD
19
P
digital supply voltage (5 V)
DGND
20
P
digital ground supply
n.c.
21
−
not connected
AVDD
22
P
analog supply voltage (5 V)
AGND
23
P
analog ground supply
2001 Oct 04
4
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
PIN
TYPE(1)
NRESET
24
O
output from the Power-on reset circuit; can be used as a reset
signal (sink current is typical 10 mA and minimum 2 mA)
n.c.
25
−
not connected
TX1
26
O
antenna output
RX
27
I
antenna input
SYMBOL
FUNCTION
Notes
1. O = output pin; I = input pin; P = power supply pin.
2. Input or output current on any pin is 1.5 mA; maximum capacitive load on any pin is 80 pF.
handbook, halfpage
1
2
3
4
5
6
7
8
9
10
11
12
13
14
27
26
25
24
23
22
21
20
19
18
17
16
15
MGU473
Fig.2 Core module with its pin connectors and pin numbering (seen from below the module).
2001 Oct 04
5
Philips Semiconductors
Product specification
HITAG core module hardware
7
HTCM400
FUNCTIONAL DESCRIPTION
7.1
System overview
The HITAG core module is a compact module used in read and write devices for the 125 kHz family.
With only a few external components (antenna coupling network, interface driver and voltage decoupling) you can use
the HTCM400 as the central part of a HITAG reader module (see Fig.3).
handbook, full pagewidth
I/O
FUNCTIONS
HOST
SYSTEM
POWER
SUPPLY
HTCM400
HITAG 1
ANTENNA
MGW324
HITAG 2
Fig.3 System overview.
7.1.1
TRANSPONDERS
The HTCM400 integrated into a read and write device can
communicate with Philips HITAG 1 and HITAG 2
transponders.
7.1.2
VDD
HOST SYSTEM
C
R2
RX
L
TxD
RxD
AGND
MGW332
Fig.4 Connecting the antenna.
I/O FUNCTIONS
The I/O lines form the connection to potential keys and
LEDs; two lines are wired as inputs and two as outputs.
7.1.4
TX1
CORE MODULE
HTCM400
The connection to the host (e.g. microprocessor or PC) is
a serial interface on CMOS level for data transmissions
over shorter distances. You can connect an RS232 as well
as an RS422 interface device. If you use an additional pin
of the HTCM400 (pin TXDEN) as control pin, you can
realize an RS485 interface.
7.1.3
antenna
R1
(optional)
handbook, halfpage
The resistor R1 has to be used if the antenna voltage is too
high (see Section 11.7). With the capacitor C the antenna
tuning is done. R2 has only to be used for antenna cable
lengths of more than 500 mm and is used for damping.
CONNECTING THE ANTENNA
Connect an antenna as shown in Fig.4
2001 Oct 04
For more details concerning the design of HITAG proximity
antennas, see Section 11.
6
Philips Semiconductors
Product specification
HITAG core module hardware
7.1.5
HTCM400
7.3.3
BEHAVIOUR WITH SEVERAL TRANSPONDERS
INTERFACE: MICROCONTROLLER - HOST
If several HITAG transponders arrive simultaneously
within the communication field of the antenna of a HITAG
proximity reader module, the ‘stronger’ transponder (the
nearer one) takes over or - under special circumstances no communication takes place. If the transponders arrive
in the field one after the other, communication is
established with the first one, all other transponders are
ignored.
The device communicates with the host (microcontroller or
PC) via a serial interface using a baud rate of 9600 baud.
Data transfer details are: 1 start bit, 8 data bits, 1 stop bit
and no parity bit, the least significant bit is sent first.
Nevertheless, it is possible to mute transponders so that
several HITAG transponders can be accessed
sequentially. This ensures that no two (or several) HITAG
transponders will ever be processed (above all written to)
accidentally at the same time.
7.3.4
An RS232 interface device can be connected to the
HTCM400. Optionally an RS422 or an RS485 device is
possible.
The transmitter receives data from the microcontroller and
modulates the carrier.
The receiver demodulates the received data and passes
them on to the microcontroller for further processing.
If a HITAG long range reader module is used, anticollision
mode is applied, which makes it possible to read and write
all the HITAG 1 transponders (theoretical up to 232) within
the communication field of the antenna simultaneously.
Because of the mutual influence of the transponder coils they detune each other if there are too many too close to
each other - the number of the transponders that can be
operated simultaneously is limited.
7.2
TRANSMITTER AND RECEIVER
7.3.5
ANTENNA
For the design of HITAG proximity antennas, see
Section 11.
7.3.6
HITAG LONG RANGE READER MODULE
The HITAG long range reader module (HTRM800)
supplied by Philips uses some of the module pins as
interface to an additional high frequency part and a Digital
Signal Processor (DSP) part.
Core module software
The software description is given in document “HTCM400,
HTRM440 Family, HTRM800 Family Interface Protocol
Reader - Host”.
7.3.7
INTERFACE: MICROCONTROLLER - HITAG LONG
RANGE BOARD
7.3
7.3.1
Core module hardware
This interface is not wired with proximity applications
(leave pins open).
EEPROM
The EEPROM is used to store non-volatile data such as
personalization data, keys, passwords, configurations and
status information.
7.3.2
MICROCONTROLLER
The microcontroller processes the protocol for the
communication between the transponders and the read
and write unit. The interface signals are converted so that
a HITAG 1 or HITAG 2 transponder is able to process
them and the outgoing signals from the transponder are
converted into interface-compatible signals.
The second essential microcontroller function is its control
function. The microcontroller activates and deactivates the
transmitter and selects the EEPROM.
2001 Oct 04
7
Philips Semiconductors
Product specification
HITAG core module hardware
7.4
HTCM400
Postal approval
Electromagnetic emission comply with the guidelines in
FTZ 17 TR 2100 and ETS 300 683. Electromagnetic
immunity complies with the guidelines in ETS 300 683.
The postal approval can only be granted for final products,
not just for components like the HTCM400. But the core
module is designed in a way that it is possible to get the
postal approval for a device including the HTCM400, if you
follow the design instructions given by Philips.
7.4.1
COMMON MODE FILTERING
Figure 5 shows the basic configuration using the
HTCM400 used to comply with the standards and some
additional circuits which are recommended.
handbook, full pagewidth
(1)
1 nF
power
supply
5 V DC
100
nF
DVDD,
AVDD
(1)
DGND,
AGND
1 nF
HTCM400
1 nF
1 nF
TxD
RxD
GND
RS232interface
1 nF
ANTENNA
TX1
RX
AGND
1 nF
1 nF
MGW326
(1) SMD filter Murata NFM61R10T102.
Fig.5 Common mode filtering.
The design consists of a virtual ground layer (drawn grey
in Fig.5). All entering wires are blocked by 1 nF ceramic
capacitors to this layer to prevent common mode
disturbances from entering the following circuits. The
2001 Oct 04
virtual ground layer is floating, it is not connected to the
ground itself.
A recommended metal housing that covers the HTCM400
would also be connected to the floating layer.
8
Philips Semiconductors
Product specification
HITAG core module hardware
7.4.2
HTCM400
FILTERING OF THE SUPPLY VOLTAGES
The transmitter of the HTCM400 is supplied via pins AVDD and AGND. Disturbances on these supply pins are amplified
and may reduce the performance of the system. For that reason especially the analog supply voltage (pin AVDD) must
be filtered in addition to the common mode filtering described in Fig.5.
On the other hand the spurious emissions at the supply connections (pins DVDD and DGND) caused by the digital parts
of the module must be limited.
A suppressor diode protects the core module from ESD to the power supply line (see Fig.6).
100 µH
handbook, full pagewidth
DVDD
100 nF
HTCM400
10 µH
VP
AVDD
100
nF
GND
22
µF
100
nF
18 V
suppressor
AGND,
DGND
10 µH
MGW327
Fig.6 Power supply filtering.
7.4.3
FILTERING OF THE ANTENNA CIRCUIT
In case of using an external antenna with shielded antenna cable, no additional filtering should be necessary. In case of
a heavy disturbed environment, an additional filter circuit is recommended when using external antennas (see Fig.7).
Using this filter will reduce the reading performance by approximately 20%.
handbook, halfpage
ANTENNA
TX1
2.2 kΩ
RX
1.68
nF
1
mH
10
kΩ
HTCM400
GND
MGW328
Fig.7 Filtering of the antenna circuit.
7.4.4
ESD PROTECTION
All I/Os should be protected by common circuits consisting of series resistors and suppressor diodes. The transmitter
output is already protected by a series resistor and internal diodes of the driving FETs. To protect the receiver’s input, a
40 V bi-directional suppresser diode at pin TX1 is recommended. If the additional filter shown in Fig.7 is used, no more
protection circuits are needed.
2001 Oct 04
9
Philips Semiconductors
Product specification
HITAG core module hardware
7.5
HTCM400
7.6.3
Security considerations
The use of cryptography (Stream Cypher), mutual
authentication and password verification prevents
monitoring and copying the data channel. Therefore, the
area of the transponder that only can be accessed
enciphered is called ‘secret area’.
Developing the HTCM400 special consideration was given
to aspects of security. The following items represent the
fundamental framework of the security concept:
• Cryptography
• Mutual authentication
To make use of cryptography you need secret data: keys
and logdata.
• Password verification and
• Cyclic Redundancy Check (CRC).
7.6
Keys are used to initialize the crypto block and logdata are
used for mutual authentication.
Data reliability
The transponders and the HITAG proximity reader module
are provided with identical transport keys and transport
logdata so that you can start operating them right away
(see Table 1).
All the commands and data transferred from the HTRM440
to the transponder are secured by Cyclic Redundancy
Check (CRC).
7.6.1
DATA PRIVACY
CRC OF A DATA STREAM BETWEEN READER
Table 1
MODULE AND TRANSPONDER
Transport values predefined by Philips.
This check is carried out in the transponder.
SYSTEM
Every data stream sent (commands, addresses and user
data) from the HTRM440 to the transponder is first
checked for data errors by a transponder-integrated 8-bit
CRC generator and then executed. Normally the
transponder responds to each data stream from the
HITAG proximity reader module with an acknowledge
signal or with a data signal or with a data block. The CRC
is formed over commands and addresses or the plain data
respectively and in the case of encrypted mode it is also
encrypted. The generator polynomial of the transponder
CRC generator reads:
HITAG 1
HITAG 2
VALUE
keyinit password
0x00000000
keys
0x00000000
logdata
0x00000000
keyinit password
0x00000000
key
0x4D494B524F4E
password TAG
0xAA4854
password RWD
0x4D494B52
In order to offer our OEM clients high flexibility, the
configuration of the transponder, memory, password, keys
and logdata can be changed. We strictly recommend to
rigorously restrict these possibilities for the end customers
(by setting the configuration page to read only, setting
password, keys and logdata to neither read nor write).
u8 + u4 + u3 + u2 + 1.............. = 0x1D
and the CRC preassignment is: 0xFF.
Detailed instructions how to use and calculate Cyclic
Redundancy Check (CRC) are available in an additional
document.
7.6.2
PARAMETER
See also “HTCM400, HTRM440 Family, HTRM800 Family
Interface Protocol Reader - Host”.
CHECKING USER DATA
7.7
This check is carried out in the HITAG proximity reader
module.
The following mechanisms ensure the operation security
of the HITAG system:
Security of the data read from the transponder by the
HITAG proximity reader module remains with the user for
reasons of flexibility. Therefore, you can choose flexible
check sums and store them in the EEPROM together with
the data. You can protect sensitive data better than less
sensitive data, thus permitting optimized operation times.
2001 Oct 04
Operating security
• Anticollision mode
• Monitoring the supply voltage
• Antenna rupture or short-circuit.
10
Philips Semiconductors
Product specification
HITAG core module hardware
7.7.1
HTCM400
ANTICOLLISION MODE
over. By muting a selected transponder (HALT mode)
another transponder that is to be found in the
communication field of the antenna can be recognized.
Anticollision mode in long range applications permits you
to process several HITAG 1 transponders simultaneously.
Theoretically up to 232 transponders can be processed
simultaneously. In practice this number is limited because
of the mutual influence of the transponders - they detune
each other, if there are too many too close to each other.
7.7.2
Supply voltage is controlled by a Watchdog circuit which
triggers a system reset if the supply voltage drops below
4.75 V or if the microcontroller fails.
In proximity applications using HITAG 1 or HITAG 2
transponders, only one transponder is handled even if
there are several transponders within the communication
field of the antenna. In this case either no communication
takes place or the ‘stronger’ or closer transponder takes
8
MONITORING THE SUPPLY VOLTAGE
7.7.3
ANTENNA RUPTURE OR SHORT-CIRCUIT
The HTCM400 does not get permanently damaged in case
of an antenna rupture or a brief antenna short-circuit.
ELECTRICAL SPECIFICATIONS
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
Power supply
VP
DC supply voltage
4.75
5.0
5.25
V
IP
DC supply current
−
−
100
mA
P
power dissipation
−
0.5
−
W
Vripple(p-p)
ripple voltage
(peak-to-peak value)
fripple is <10 kHz; note 1
−
−
5
mV
fripple is 10 to 20 kHz; note 1
−
−
25
mV
fripple is ≥20 kHz; note 1
−
−
40
mV
Modulation
mTX
modulation ratio of reader module Amplitude Shift Keying (ASK)
to transponder
−
100(2)
−
%
mRX
modulation ratio of transponder to Amplitude Shift Keying (ASK);
reader module
note 3
−
−
−
%
Temperature
Toper
operating temperature
−25
−
+85
°C
Tstg
storage temperature
−40
−
+85
°C
Notes
1. With the power supply filter described in Section 7.4.2.
2. The carrier is periodically blanked completely, the information is located in the intervals between the pauses.
3. Modulation ratio depending on the distance between transponder and reader module.
2001 Oct 04
11
Philips Semiconductors
Product specification
HITAG core module hardware
9
HTCM400
MECHANICAL SPECIFICATIONS
9.2
The outer dimensions of the PCB are: 86 × 40 × 7 mm.
The module consists of the Printed-Circuit Board (PCB)
and one 14-pole and one 13-pole pin connector that
protrudes from the PCB.
9.1
Dimensions
The module including the pin connectors is approximately
18 mm high.
Mounting the module
You can mount the module onto a base printed-circuit
board by soldering or plugging.
handbook, full pagewidth
26.7
7.3
0.64
2.54
25.4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
27
26
25
24
23
22
21
20
19
18
17
16
15
60.0
86.0
18
40
MGW325
26.3
13.0
32.0
4.0
40.0
Dimensions are in mm.
Fig.8 Dimensions (seen from below the module) and pins protruding.
2001 Oct 04
12
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
10 APPLICATION INFORMATION
10.2
10.1
In order to be able to operate two systems side by side
without negative influence on communication ranges, you
must place the antennas at a minimum distance of four
times the antenna diameter. If you place them at a closer
distance be sure to use suitable shielding or
synchronization.
Metallic environment, interferences
The communication range is impaired by metallic
environment and electromagnetic interferences (e.g.
monitors and keyboards). Therefore, you should keep a
distance of at least the antenna’s diameter to metallic
surfaces or loops as well as to electromagnetic
interferences. If this is not possible, you have to take
preventive measures such as using ferrites for
transponders and antennas or shielding for antennas.
10.3
Distance between two antennas
To build a proximity reader
handbook, full pagewidth
other 125 kHz
transponders
CORE MODULE
HTCM400
serial interface
HITAG
antenna
tags
MGW330
Fig.9 Block diagram of proximity reader module.
10.3.1
CONNECTION OF THE HTCM400 IN ORDER TO BUILD A PROXIMITY READ AND WRITE DEVICE.
A few external components are needed to make the HTCM400 a proximity read and write device (see Fig.10).
handbook, full pagewidth
POWER
SUPPLY
filter on/off switch
(optional)
DVDD
OUT1
AVDD
OUT2
DGND
IN1
AGND
IN2
I/O FUNCTIONS
(if needed)
CORE MODULE
HTCM400
SERIAL
INTERFACE
DRIVER
(if needed)
RxD
TX1
TxD
RX
TXDEN
AGND
ANTENNA
COUPLING
MGW333
Fig.10 Building a proximity read/write device.
2001 Oct 04
13
Philips Semiconductors
Product specification
HITAG core module hardware
10.3.2
HTCM400
POWER SUPPLY
distances the transmission can be done over an RS232
interface, longer distances require integration of an RS485
or RS422 interface component. If you use an RS485
interface, pin TXDEN is used as control pin.
The HTCM400 requires a DC voltage of 5 V ± 5% and it is
absolutely necessary to use a low resistance (<0.7 Ω)
power supply. Voltage regulation is required and separate
supplies for analog and digital parts are recommended.
See Section 8 for maximum allowed power supply ripple
amplitudes.
10.3.3
10.3.4
I/O FUNCTIONS
If necessary, you can connect these inputs and outputs to
drivers for LEDs and switches.
INTERFACE DRIVER
Signal transmission for direct connection to the host can
be done over the serial CMOS interface. For short
10.4
To build a long range reader
handbook, full pagewidth
other 125 kHz
transponders
RF PART
CORE MODULE
HTCM400
serial interface
DSP
HITAG
tags
antenna
MGW331
Fig.11 Block diagram of long range reader module.
10.5
• Interference received by the antenna because of an
external noise source (e.g. monitor or keys). Remedial
measure: removal of the antenna from the interfering
area
Possible sources of errors by connecting the
HTCM400
The following error list should be checked if any error (e.g.
read and write distances that do not reach the specified
values) occurs:
• Connecting cables of the antenna changed by mistake
• Antenna is mounted in metal environment. Remedial
measure: mount a non-metal space keeper between the
antenna and the metal
• Power supply cable not mounted correctly
• Bad filtering of the power supply; remedial measure:
filtering as described in Section 7.4.2
• Antenna is not designed following the design
instructions of Section 11
• DC power supply not within the specified range
(VP = 5 V ± 5%)
• Inductance of the antenna is too high
• RS232 interface not connected correctly
• Quality factor of the antenna is too high (Q > 40)
• Interference received by the HTCM400 because of the
digital part of a possible additional circuit board.
Remedial measure: shielding of the additional circuit
board
• Antenna current is too high
• Antenna voltage is too high.
• Interference received by the HTCM400 because of an
external noise source. Remedial measure: housing of
metal or shielding
2001 Oct 04
14
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
11 INSTRUCTIONS FOR BUILDING HITAG
PROXIMITY ANTENNAS
within the limit values 3 and 1. If the ratio is too big or too
small read/write distances can decrease and difficulties
during data transmission may occur. For applications in
which the transponders are only to be read, you can also
use antennas that do not meet these instructions.
The antenna is an important part in the data transmission
process between read and write device and transponder.
Therefore, you should be particularly careful when
implementing the antenna in order to achieve optimum
results.
11.1
Basics
Figure 12 shows the general architecture of a HITAG
proximity antenna and its connection to the HTCM400.
An essential aspect in dimensioning HITAG proximity
antennas is the ratio between the antenna diameter and
the diameter of the transponder coil. This ratio should be
handbook, full pagewidth
R1
TX1
Cs
Ia
Vo
Cs
RX
R2
L
VL
CORE
MODULE
Ls
R2
Rs
AGND
ANTENNA
MGW273
antenna equivalent
circuit
Fig.12 Architecture of a proximity antenna.
The resistor R1 (22 Ω) in Fig.12 is used as current limiter.
It protects the output stage in the event of a possible short
circuit in the antenna and is already integrated in the
HTCM400. R2 (approximately 600 to 1000 Ω) has only to
be used for antenna cable lengths of more than 50 cm.
When developing an antenna, it is important to take into
consideration the read/write device limits, i.e. maximum
antenna current and maximum voltage at the receiver
input. With an output voltage Vo of approximately
2.5 V (p-p) the following limits apply to the HTCM400:
• Maximum antenna current is 100 mA (p-p)
• Maximum input voltage at the receiver (VL) is 32 V (p-p).
2001 Oct 04
15
Philips Semiconductors
Product specification
HITAG core module hardware
11.2
HTCM400
Antenna coil
11.3
The inductance of the coil should be between
350 and 500 µH.
Measuring the inductance
The inductance of the coil designed according to the
instructions as given in Section 11.2 can be measured
using the measuring set-up as shown in Fig.13.
The antenna quality factor (Q) should be
approximately 40.
2×π×f×L
Q = -----------------------------Rs
handbook, halfpage
If the Q factor is too high, it must be reduced with an
additional resistor. It is better not to use this additional
resistor, but instead to use a smaller wire diameter of the
coil.
Ia
R
47 Ω
f = 125 kHz
L
The following formula describes the approximate
calculation of the number of windings for a desired
inductance and antenna geometry:
VL
MGW275
1.9
a
L = 2 × a × ln  ---- – K × N
D

Fig.13 Measuring the inductance of the coil.
where:
L is desired inductance in nH
A sinus signal of 125 kHz is fed using a function generator.
If you measure the current Ia and the antenna voltage VL
you can calculate the inductance according to the formula:
VL
L = -------------where ω = 2 × π × f .
ω × Ia
a is antenna circumference in cm
D is wire diameter in cm
N is number of windings
K is a geometrical constant:
For a circular antenna K = 1.01
11.4
For a square antenna K = 1.47.
For optimal performance, the antenna cable length should
not exceed 5 m.
a
Remark: the factor K is normally much smaller than ---- and
D
can therefore be left out: N ≈
1.9
2001 Oct 04
Antenna cable length
L
---------------------------------a
2 × a × ln  ----
 D
16
Philips Semiconductors
Product specification
HITAG core module hardware
11.5
HTCM400
Antenna tuning
You have to tune the antenna in its final form with the connecting cable. You must not make any changes to the antenna
coil or the connecting cable after you finished tuning because mechanical changes influence the electrical values and
the antenna is detuned again.
R1
handbook, full pagewidth
47 Ω
Cs
Va
R2
Vo
f = 125 kHz
L
MGW274
R3
1Ω
VR
Fig.14 Tuning the antenna.
A sinus signal of 125 kHz is fed to the antenna using a
frequency generator. You measure the voltages Va and VR
with an oscilloscope. Then you change the frequency until
Va and VR are in phase. If the resonance frequency now is
too high, you have to increase CS. If it is too low, you have
to decrease CS.
11.6
Determining the serial resistance of the
antenna
Use an oscilloscope to measure Va and VR at a frequency
of 125 kHz. You can calculate the serial resistance RS of
V
the antenna with the following formulas: I a = ------R- and
R3
The aim is to get a resonance frequency of 125 kHz
using CS.
V
R s = -----aIa
The resonant frequency has to be in the range of
125 ± 4 kHz.
11.7
Checking the antenna voltage VL
Before connecting the antenna to the read and write
device in Fig.15, you must carry out a check calculation of
the input level of the read and write device according to the
next formulas in order to prevent damage.
handbook, full pagewidth
R1
Re
TX1
Ia
Vo
Cs
RX
R2
L
VL
CORE
MODULE
AGND
MGW276
Fig.15 Calculation check of the input level.
2001 Oct 04
17
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
of the metal shorter than the maximum antenna
diameter)
Vo
I a = ---------------------------------R1 + R s + R e
• Measurement of the inductance L of the antenna is
described in Section 11.3
Vo ≈ 2.5 V
• Determination of the serial capacitor CS is described in
Section 11.5
VL = L × ω × Ia where ω = 2 × π × f (f = 125 kHz)
The maximum value for VL reads 32 V (p-p), safeguarding
against damage to the input level of the read/write device:
Remark: the capacitance of the antenna supply cable
can be measured or found out in the data sheet of the
cable (e.g. Cp = 180 pF/m)
• With VL < 32 V (p-p) the resistance Re can be omitted
• With VL > 32 V (p-p) you have to calculate and insert Re
according to the following formula:
Vo
R e = L × ω × ----------------- – R1 – R s and
V L(max)
• Now the antenna has to be tuned according to
Section 11.5. The tuning is acceptable if the resonant
frequency is within a range of 125 ± 4 kHz
• The serial resistance Rs of the antenna is the impedance
of the tuned antenna and is an ohmic resistance at the
resonance frequency (f = 125 kHz). It can be calculated
as shown in Section 11.6
Re ≥ L × ω × 0.078 − 22 − Rs
11.8
Procedure for practical antenna design
• To get a satisfactory reading distance the quality factor
of the antenna coil (for non-metal environment) should
be approximately Q = 40. The quality factor of a coil is
2×π×f×L
ω×L
calculated as follows: Q = ------------- = -----------------------------Rs
Rs
The procedure how to design a HITAG proximity antenna
is described in the previous sections. The main steps are
the following:
• The desired inductance for the antenna coil can be
chosen in a range between 350 and 500 µH; e.g.
L = 420 µH
• By knowing RS and the dropping resistor (R1 = 22 kΩ) it
is possible to calculate the current Ia and the antenna
voltage VL.
• The number of windings N can be calculated with the
following formula: N =
1.9
L ( nH )
-------------------------------------------------a
2 × a × ln ×  ---- – K
 D
It is very important to calculate the antenna voltage
before connecting the antenna to the HTCM400 to avoid
damage. Is the calculated value of VL higher
than 32 V (p-p) a resistor Re has to be integrated to
protect the module output circuit. The resistor has to be
placed as shown in Section 11.7
For L = 420 µH:
N=
1.9
420000
633
-------------------------------------------- = --------------------------------a

 a
2 × a × ln ---- – K
1.9 a × ln --- D
 D
• After checking the antenna voltage connect your
antenna to the HTCM400 and measure the read/write
distances with your transponders. If the read/write
distances do not fulfil your expectations, the following
points should be considered:
Remark: the factor K (see Section 11.2) normally is
a
much smaller than ---- and therefore can be left out.
D
– The size of the antenna and the size of the
transponder have to be in a defined ratio (between 3
and 1). That means, if you increase the antenna over
a certain size, the maximum read/write distances will
decrease by the use of the same transponder
• Now the antenna can be built up with the desired
dimensions (circumference a) with the calculated
number of turns.
Remark: the antenna coil must be changed afterwards
because with the mechanical dimensions the electrical
specifications are changing too. That means the number
of turns, the shape, arrangement of the coil windings
and antenna supply cable must be in their final form.
– The optimal shape of the antenna coil is a circle. The
performance of a square shaped coil is much better
than that of a rectangular shaped coil (with the same
circumference)
Remark: metal influences the electrical characteristics
of the antenna very much. That is why all future tasks
have to be done with the antenna in its final environment
if metal will be in the antenna’s neighbourhood (distance
2001 Oct 04
– To get better read/write distances the quality factor of
the antenna coil should be increased, but it must not
be higher than Q = 40. This can be reached by the
following measures:
18
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
In this case cards and coins can be used and the following
approximate communication distances should be
achieved:
– All conducting material has to be removed from the
antenna environment
– A thicker wire can be used for the coil
Read distances with HITAG 1 and 2 card: 120 mm
– Ferrite can be placed behind the antenna coil to
concentrate the field
Read distances with HITAG 1 and 2 coin: 65 mm.
– Extension of the antenna area
The third antenna configuration is the smallest one:
– There can be better results by trying another number
of turns.
Ø 0.224 mm Cu; lacquer wire; 85 turns
Diameter of the turns (internal) is 35 mm
Attention: all these measures must not differ from the
antenna design instructions of Section 11.
Tuning frequency is 125 kHz
Tuning capacity depending on the length of the antenna
cable and the exact way of winding.
Remark: with additional dropping resistors R1 and Re the
quality factor of the whole antenna system is
approximately 15.
11.9
Using this antenna coins and pills can be operated up to
the following approximate distances:
Read distance with HITAG 1 coin: 58 mm
Reference antennas
Read distance with HITAG 1 pill: 28 mm.
Designing an antenna in the way described in Chapter 11
you could use the following values:
All distances are given in free air at room temperature.
Ø 0.4 mm Cu; lacquer wire; 35 turns
Diameter of the turns (internal) is 145 mm
12 SURVEY OF REFERENCED DOCUMENTS
Tuning frequency is 125 kHz
CATEGORY
Tuning capacity depending on the length of the antenna
cable and the exact way of winding.
Data sheet
This antenna is best suitable for HITAG 1 and 2 cards. In
this performance reading distances of approximately
150 mm should be achieved.
A further antenna configuration:
Ø 0.224 mm Cu; lacquer wire; 52 turns
Diameter of the turns (internal) is 65 mm
Tuning frequency is 125 kHz
Tuning capacity depending on the length of the antenna
cable and the exact way of winding.
2001 Oct 04
19
TITLE
“HTCM400, HTRM440 Family,
HTRM800 Family HITAG Interface
Protocol Reader - Host”
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
13 DATA SHEET STATUS
DATA SHEET STATUS(1)
PRODUCT
STATUS(2)
DEFINITIONS
Objective data
Development
This data sheet contains data from the objective specification for product
development. Philips Semiconductors reserves the right to change the
specification in any manner without notice.
Preliminary data
Qualification
This data sheet contains data from the preliminary specification.
Supplementary data will be published at a later date. Philips
Semiconductors reserves the right to change the specification without
notice, in order to improve the design and supply the best possible
product.
Product data
Production
This data sheet contains data from the product specification. Philips
Semiconductors reserves the right to make changes at any time in order
to improve the design, manufacturing and supply. Changes will be
communicated according to the Customer Product/Process Change
Notification (CPCN) procedure SNW-SQ-650A.
Notes
1. Please consult the most recently issued data sheet before initiating or completing a design.
2. The product status of the device(s) described in this data sheet may have changed since this data sheet was
published. The latest information is available on the Internet at URL http://www.semiconductors.philips.com.
14 DEFINITIONS
15 DISCLAIMERS
Short-form specification  The data in a short-form
specification is extracted from a full data sheet with the
same type number and title. For detailed information see
the relevant data sheet or data handbook.
Life support applications  These products are not
designed for use in life support appliances, devices, or
systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips
Semiconductors customers using or selling these products
for use in such applications do so at their own risk and
agree to fully indemnify Philips Semiconductors for any
damages resulting from such application.
Limiting values definition  Limiting values given are in
accordance with the Absolute Maximum Rating System
(IEC 60134). Stress above one or more of the limiting
values may cause permanent damage to the device.
These are stress ratings only and operation of the device
at these or at any other conditions above those given in the
Characteristics sections of the specification is not implied.
Exposure to limiting values for extended periods may
affect device reliability.
Right to make changes  Philips Semiconductors
reserves the right to make changes, without notice, in the
products, including circuits, standard cells, and/or
software, described or contained herein in order to
improve design and/or performance. Philips
Semiconductors assumes no responsibility or liability for
the use of any of these products, conveys no licence or title
under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that
these products are free from patent, copyright, or mask
work right infringement, unless otherwise specified.
Application information  Applications that are
described herein for any of these products are for
illustrative purposes only. Philips Semiconductors make
no representation or warranty that such applications will be
suitable for the specified use without further testing or
modification.
2001 Oct 04
20
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
NOTES
2001 Oct 04
21
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
NOTES
2001 Oct 04
22
Philips Semiconductors
Product specification
HITAG core module hardware
HTCM400
NOTES
2001 Oct 04
23
Philips Semiconductors – a worldwide company
Contact information
For additional information please visit http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
For sales offices addresses send e-mail to: [email protected]
SCA73
© Koninklijke Philips Electronics N.V. 2001
All rights are reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner.
The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed
without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license
under patent- or other industrial or intellectual property rights.
Printed in The Netherlands
613502/02/pp24
Date of release: 2001
Oct 04
Document order number:
9397 750 08333