MELEXIS MLX90121

MLX90121
13.56MHz RFID Transceiver
Features and Benefits
Applications
(1)(3)
Conforms with ISO14443A
(2)
Conforms with ISO14443B
(3)
Confroms with ISO15693
Programmable encoder and decoder
Low external component count
Portable data terminals
Access control readers
Contact-less payment terminals
Smart label printer
(1).Purchase of MLX90121s doesn’t imply any grant of any ISO14443A license. Customers are advised to sign patent licensing
agreements with all third parties, especially those companies listed in the introduction of the corresponding standard.
(2) RATP / Innovatron Technology
(3) Conformance with ISO/IEC15693 “long distance mode” (6.6kb/s ASK) and ISO/IEC14443A is limited to a temperature range from
O°C to 85°C.
Ordering Information
Part No.
MLX90121
MLX90121
Temperature Suffix
C (0°C to 70°C)
E (-40°C to 85°C)
Package Code
FR (Lead free SSOP20, 20 9 mils)
FR (Lead free SSOP20, 2 09 mils)
1. Functional Diagram
2. Description
MLX90121
Attenuation
resistor
RX
Analog
functions
Digital
functions
TX
Impedance
matching
Serial data
interface
Microcontroller
3901090121
Rev. 007
Option code
---
The MLX90121 is an ISO compliant 13.56MHz
RFID transceiver integrated circuit.
The main features include user selectable
modulation depth in write mode, whereas single
sub-carrier ASK, FSK and PSK modulations are
recognized in the read mode.
The receiver is based on a diode envelope
detector, followed by an IF filter and amplifier. A
logarithmic amplifier is used for single subcarrier ASK detection, ensuring fast and clean
data recovery. The limiting output of the log amp
is used for FSK and PSK recovery.
The transmitter uses a built in open drain output
transistor, which can provide up to 250 miliwatts
of RF power to a 50 ohms load with a 5 volts
power supply using the recommended matching
network. This is suitable for most short to mid
range applications. A simplified antenna and
matching network can be used, at the expense
of a reduced reading range, for example in
hand-held reader applications.
The chip is configured with a serial interface. A
synchronization signal is available when the
majority voting is used.
Digital part contains ASK, FSK (423 / 484kHz)
and
PSK
(847kHz)
decoders
and
a
programmable encoder to facilitate data
handling with a low cost microcontroller. The
encoder can be programmed with 6 different
patterns.
The chip can also be used as an analog frontend, in direct mode.
Page 1 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
TABLE OF CONTENTS
FEATURES AND BENEFITS ....................................................................................................................... 1
APPLICATIONS............................................................................................................................................ 1
ORDERING INFORMATION......................................................................................................................... 1
1.
FUNCTIONAL DIAGRAM................................................................................................................... 1-1
2.
DESCRIPTION.................................................................................................................................... 2-1
3.
GLOSSARY OF TERMS ....................................................................................................................... 3
4.
ABSOLUTE MAXIMUM RATINGS ....................................................................................................... 3
5.
MLX90121 ELECTRICAL SPECIFICATIONS ...................................................................................... 3
6.
MLX90121 SPECIFIC SPECIFICATIONS............................................................................................. 4
7.
GENERAL DESCRIPTION .................................................................................................................... 6
8.
APPLICATIONS INFORMATION .......................................................................................................... 7
9.
BLOCK DIAGRAM ................................................................................................................................ 8
10. DIGITAL INTERFACE ........................................................................................................................... 8
11. OPERATING MODES............................................................................................................................ 9
11.1.
DEFINITIONS ...............................................................................................................................................9
11.2.
CONFIGURATION MODE ..............................................................................................................................9
11.3.
COMMUNICATION MODES .........................................................................................................................10
11.3.1. Transmission ........................................................................................................................................10
11.3.2. Reception..............................................................................................................................................14
11.4.
POWER MODES..........................................................................................................................................18
11.5.
XBUF OUTPUT .........................................................................................................................................19
12. CONFIGURATION REGISTERS ......................................................................................................... 20
13. CONFIGURATION REGISTERS: ISO CONFIGURATION EXAMPLES ............................................ 22
14. STANDARD INFORMATION REGARDING MANUFACTURABILITY OF MELEXIS PRODUCTS
WITH DIFFERENT SOLDERING PROCESSES ........................................................................................ 23
15. ESD PRECAUTIONS........................................................................................................................... 23
16. PACKAGE INFORMATION................................................................................................................. 24
17. DISCLAIMER ....................................................................................................................................... 26
3901090121
Rev. 007
Page 2 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
3. Glossary of Terms
RFID
Radio Frequency IDentification
ISO
International Organization for Standardization / International Electro-technical Commission.
ASK
Amplitude Shift Keying
FSK
Frequency Shift Keying
PSK
Phase Shift Keying
4. Absolute Maximum Ratings
Parameter
Symbol
Condition
Min
Max
Unit
Supply voltage (VDD with respect to VSS)
VDD
DC
Input voltage on any pin (except TX)
Vin
Maximum power dissipation (without heat sink)
Pmax
500
mW
Maximum junction temperature
Tj
+150
ºC
Storage temperature
Tstor
+150
ºC
-0.3
6
V
-0.3
VDD+0.3
V
-55
Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute-maximumrated conditions for extended periods may affect device reliability.
5. MLX90121 Electrical Specifications
TA = -40 ºC to +85 ºC, or 0ºC to +70 ºC according to the version, VDD = 5Volts, unless otherwise noted.
On board resonator is used.
Parameter
Symbol
Test Conditions
Min
Typ
Max Units
General DC Parameters
Operating supply voltage range
VDD
VDD with respect to VSS
Standby current consumption
Istb
VDD = 5.5 V - TA = +85 ºC
5
5.5
V
3
30
µA
0.1
10
µA
VDD = 5.5V - Analog section off
3
5
mA
VDD = 3V, XBUF output disabled
1
3
mA
50 Ohms load
80
120
mA
VDD = 3V
45
70
mA
TA = +25 ºC
Idle mode current consumption
Transmit current
3901090121
Rev. 007
Idle
Itr
Page 3 of 26
2.7
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
6. MLX90121 Specific Specifications
DC Operating Parameters TA = -40oC to 85oC, or 0oC to +70oC according to the version, VDD = 5V (unless
otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Transmitter specifications
Peak voltage applied on drain of
output transistor
32
V
600
mW
Output transistor power dissipation
With heat sink
Output transistor ON resistance
Id = 50 mA
2
Output power for five volts
operation
See note 1
250
Amplitude modulation depth
adjustment range, in 10% mode,
with external resistor connected
between RMOD pin and ground.
See note 1
0
Amplitude modulation depth in
10% mode with nominal external
resistor (10Ω)
See note 1
8
Minimum depth for 100% ASK
See note 1
40
Rise time for 100% ASK
50 Ohms load - 5% to 60%
0.2
0.4
µs
50 Ohms load - 5% to 90%
0.3
1.5
µs
Fall time for 100% ASK
50 Ohms load - 100% to 5%
0.6
µs
Rise and fall time for 10%
modulation depth ( nominal
external resistor used)
50 Ohms load
0.2
µs
100
kΩ
10
5
Ω
mW
90
%
14
%
dB
Receiver specifications
Small signal input impedance (RX)
Input RF voltage range (RX – VSS)
With 4.7kΩ series external resistor
Receiver sensitivity
See note 2
2
Vpp
-45
dBm
200-1400
kHz
Gain, in FSK mode (FM output)
120
dB
Gain, in ASK mode (AM output)
80
dB
FSK IF filter cut off points
3901090121
Rev. 007
Page 4 of 26
-35
3
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Serial link and digital I/O
Output current drive
Iol
Vol ≤ 0.4 Volt
4
Output voltage low
Vol
Iol max=4mA
0
0.2
0.4
V
Output voltage high
Voh
Ioh max=4mA
4.6
4.8
5
V
Input voltage high
Vih
0.7 * VDD
VDD + 0.3 V
Input voltage low
Vil
-0.3
0.3 * VDD V
CK pulse
TCK
General setup time
“0” level pulse or “1” level pulse
mA
500
ns
Ts
60
ns
General hold time
Th
60
ns
Pulse time between successive
registers writing
Tmw
5
µs
Crystal Oscillator
Frequency range
Fxtal
Start-up time
Tstart
ISO compliant applications
13.56
2
5
ms
50
100
Ω
1
VDD
VPP
1
VDD
VPP
Xtal series resistance
External clock signal
specifications
MHz
see note 3
Min sine wave amplitude, AC
coupled
Input on pin XTAL2
Min sine wave amplitude, DC
coupled
Input has to be centered around
Vdd/2
Input on pin XTAL2
XBUF output specifications
XBUF Low Level (Col)
1K load resistor
0.1
V
XBUF High Level (Coh)
1K load resistor
4.8
V
Rise and fall times (10%-90%)
1K load resistor//12pF
3
ns
Notes
1. Parameter measured using recommended output matching network.
2. This parameter is measured using a base band signal for all specified modulation modes. The
measurement is made at the DOUT output with the input diode detector bypassed.
3. The external clock symmetry is of paramount importance. It has a direct influence on the transmitter
output power. When using a sine wave as external clock input, it must not show visible distortion. In
case a square wave is used, its duty cycle has to be equal to 50%.
3901090121
Rev. 007
Page 5 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
7.
General Description
Power supply
The 90121 requires a nominal 3 or 5 volts external
power supply. Operation is guaranteed between
2.7 and 5.5 Volts. The current drain depends on
the antenna impedance and the output matching
network configuration. Care must be taken about
the power supply: power supply ripple and noise
will severely degrade the overall system
performance.
Transmitter
The output transistor is a low Ron MOSFET. The
drain is directly accessible on the TX pin. A
recommended application schematic optimized to
drive a resistive fifty ohms antenna with a five
volts power supply is provided as a part of this
specification. A simple resonant circuit or/and a
simpler matching network can be connected to the
output. In that case, the general performance and
harmonic suppression will be reduced.
100 % modulation is achieved by means of gating
the square wave drive of the output transistor.
A variable modulation depth is obtained by means
of switching a resistor in series with the output
transistors’ source connection. An external
resistor provides the default modulation depth
setting. Increasing this external resistor will
increase the modulation depth.
Receiver
The receiver input is typically connected to the
antenna through an external resistor. The
modulation from the tag is then recovered by
means of a diode envelope detector.
FSK and PSK recovery
The demodulated input signal is amplified and
band pass filtered. The signal is then hard limited
by a logarithmic amplifier, and fed to the digital
section. PSK decoded, FSK decoded or a direct
FSK signal can be used for further decoding.
ASK recovery
For ASK recovery, the high pass sections of the
band pass filters are removed, to avoid falling
edge degradation by the filter settling time. The
signal is DC coupled and fed to the input of the
logarithmic amplifier. The logarithmic amplifier
works as a high gain amplifier and at the same
time it generates the envelope of the ASK signal.
The demodulated output from the log amp is then
3901090121
Rev. 007
fed to a comparator. To avoid signal degradation,
the time constant of the comparator has to be
switched from fast response during acquisition to
a slow time constant during the tags response.
This is done by switching the CK signal at the
beginning of the response of the tag. The
recovered data stream is fed to the digital section
for further processing.
Majority Voting
Both FSK/PSK or ASK can use the Majority
Voting function that will filter for noise and jitter,
that will correct distorted signals and will hence
improve performance.
Reference clock and internal oscillator
The reference clock may be obtained externally
by applying a suitable clock signal to the XTAL1
pin. A sine wave centered at VCC/2 or a CMOS
logic compatible signal is an acceptable external
system clock. The built-in reference oscillator will
work either with a quartz crystal or a ceramic
resonator. The nominal system clock frequency is
13.56 MHz.
Reset defaults and power management
After a power on reset has been performed, the
device is put in its default configuration. There are
three power modes available. In the transmission
mode, the device is fully powered. In the idle
mode, only the reference oscillator is running.
This allows for a fast start up. In the power down
mode, the device internal bias system is
completely switched off, offering essentially a zero
state.
Serial communication interface
The communication interface normally uses 6
wires:
-
Page 6 of 26
CK: serial clock input
DIN: data input
DOUT: data output
DSYNC: synchronization output for DOUT
MODE: configuration or communication
selection input
RTB: reception or transmission selection
input.
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
8.
Applications Information
This schematic has been optimized to drive a fifty ohms resistive antenna, using a five volts power supply.
Functional description
The transmitter output TX is connected to the supply by means of a choke L3. C3 is added to avoid a high
dV/dt at the TX output in case of a sudden interruption of the current in the choke. C3 is chosen high
enough to protect the chip, but low enough to keep the resonance of L3-C3 well above 13.56 MHz.
The transmitter signal is coupled with DC blocking capacitor C2 to the antenna matching network, which is
a T network made up by L2, CV1 and L1. CV1 allows a proper matching between the 50Ohm antenna
and the output impedance of the transmitter stage.
The receiver part of the chip gets its signal directly from the antenna by means of R1. It limits the voltage
swing at the RX pin to a level in between the supplies.
One should take care to properly decouple the power supplies of the chip. Especially the Vdd1 supply
which is used for the transmitter output. Any amplitude noise on that supply is AM modulated on the
carrier and will hence be perceived as noise by the receiver part. The same holds for any phase noise that
gets introduced into the quartz oscillator.
For the signal that goes to- and from the microcontroller: one should take care to keep them as far as
possible from the analog parts and the quartz oscillator. To do a first evaluation, it is highly recommended
to use the MLX90121 evaluation board that can be ordered from Melexis. The clock for the microcontroller
can also be derived from the XBUF pin. This pin provides a 13.56MHz buffered clock or 13.56MHz divided
by 2.
3901090121
Rev. 007
Page 7 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
9. Block Diagram
Digital
AM
RX
FM
Majority
Voting
FSK
Decoder
DOUT
PSK
Decoder
Programmable
Encoder
DIN
PA
TX
XTAL
RMOD
XBUF
13.56MHz
10. Digital Interface
The MLX90121 is driven by four signals: MODE and RTB pins are used to select the operating mode and
DIN and CK pins are used to configure the chip and to transmit data.
The MLX90121 has two signal outputs. DOUT contains the decoded response of the transponder and
DSYNC is used as a synchronization output by the microcontroller.
Pin Name
I/O
Function
MODE
I
0 = Configuration Mode, 1 = Communication Mode
RTB
I
0 = Transmission Mode, 1 = Reception Mode
DIN
I
Data Input for Transmission or Configuration
CK
I
Clock and Trigger
DOUT
O
Data Output from Reception or Configuration
DSYNC
O
Data Synchronization Clock for Transmission or Reception
Function Summary
MODE
RTB
Function
0
0
Configuration
1
0
Transmission
0
1
Reserved (*)
1
1
Reception
(*) the reserved mode is for manufacturing purpose only and should not be applied by the user.
3901090121
Rev. 007
Page 8 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
11.
Operating Modes
11.1. Definitions
There are two main operating modes:
• MODE = 0
: Configuration Mode
• MODE = 1
: Communication Mode
The configuration mode allows writing in the configuration registers. It will configure all parameters in the
transceiver.
The communication mode allows communicating with a transponder. Different options are available:
• Direct transmission: The transmission protocol is handled by an external microcontroller.
• Hardware transmission: The low level protocol is handled by an internal programmable encoder. It
allows using a low cost microcontroller.
• Direct reception: The reception protocol is handled by an external microcontroller.
• Hardware reception: FSK/PSK decoders and Majority Voting can be enabled to allow using a low
cost microcontroller.
11.2. Configuration Mode
Registers Addresses
For configuration purposes, users have access to 13 eight bit registers, which can be addressed using a 4
bit address.
Address
Register name
0
AnalogConfig
1
PowerState
2
Reserved (*)
3
DigitalConfig
4
EncoderSym0
5
EncoderSym1
6
EncoderSym2
7
EncoderSym3
8
EncoderSym4
9
EncoderSym5
10
EncoderTimeRef
11
DecoderTimeRef
12
LTC
(*) the reserved register is for manufacturing purpose only and should not be used.
Write Configuration Registers
First the MODE line is asserted low to enable the configuration mode. Then data is fed serially into the
chip with the CK and DIN lines. Data on the DIN line is read on the rising edge of CK. The first four bits on
DIN are the register address and the eight following bits are the data. Address and data fields are written
MSB (Most Significant Bit) first.
3901090121
Rev. 007
Page 9 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
MODE
DIN
Address
Data
CK
MSB
LSB MSB
LSB
RTB
After sending address and data, the MODE line is asserted high and the chip is ready to receive the next
register configuration.
Signal
Assign
MODE
0
RTB
0
DIN
4-bit Address + 8-bit Data
CK
12 clock pulses
DOUT
x
DSYNC
x
Notes
1. If a register does not contain eight bits, write ‘0’ in the unused bit.
2. When MODE is asserted high, the chip is in communication mode. If the encoder is disabled (by
default), DIN has to be kept at ‘1’ to avoid any modulation on the antenna.
3. In case of successive registers writings, it is mandatory to have MODE asserted high for at least
Tmw = 5µs in between each access, as shown in the following diagram.
Writing 1
Tmw
Writing 2
MODE
CK
11.3. Communication Modes
11.3.1. Transmission
11.3.1.a. Analog Setup
For the transmission, the modulation depth has to be chosen. This is done by the TModIndex bit of the
AnalogConfig register, which selects the modulation index: 10% or 100%.
The modulation index can be further tuned by means of the external RMOD resistor.
3901090121
Rev. 007
Page 10 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
11.3.1.b. Direct Transmission
Before analog processing, data transmission can be either direct or pre-processed by means of hardware
accelerators. Direct transmission can be performed with the following setup:
Signal
Assign
MODE
1
RTB
0
DIN
Data to transmit
CK
0
OUT
x
DSYNC
x
Data has to be transmitted in real time by the microcontroller on DIN input. The modulation is done when
DIN is asserted low, so by default DIN has to be asserted high. If a configuration register has to be
written, keep DIN high when MODE is asserted low. In configuration mode, the field is held without
modulation independently of DIN.
11.3.1.c. Hardware Encoding Transmission
This programmable encoder allows predefining six different patterns of 8 bits. The encoder is selected by
setting the bit EncoderEn in the DigitalConfig register.
Symbol Setup
The six symbols are called EncoderSym0 to EncoderSym5. There is a seventh symbol which is hardcoded to 0xFF (11111111).
A symbol is built with 8 bits as shown in the following figure.
Symbol
Code
1
0
1
1
1
0
1
1
ISO Examples
The ISO15693 protocol, mode 1 out of 4, is implemented using six symbols as shown in the following
table. Start of frame (SOF), end of frame (EOF) and pulses are all encoded using one symbol.
ISO15693 (1 out of 4)
3901090121
Rev. 007
Symbol
Name
Code
Sym0
Pulse1
10111111
Sym1
Pulse2
11101111
Sym2
Pulse3
11111011
Sym3
Pulse4
11111110
Sym4
SOF
01111011
Sym5
EOF
11011111
Page 11 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
The ISO15693 protocol, mode 1 out of 256, is implemented using three symbols. Start of frame (SOF),
end of frame (EOF) and pulses encoding result of the combination of these three symbols.
ISO15693 (1 out of 256)
ISO15693 (1 out of 256)
Symbol
Code
Name
Combination
Sym0
11111111
SOF
Sym2+2*Sym0+Sym1
Sym1
11110000
EOF
Sym0+Sym2
Sym2
00001111
Pulse 1 to 256
255*Sym0+Sym1
Note
•
The position of the symbol Sym1 encodes pulses from 1 to 256. For example: Pulse1 = Sym1 +
255*Sym0 and Pulse45 = 44*Sym0 + Sym1 + 211*Sym0.
The ISO14443 -A protocol is implemented using three symbols, according to the ISO specification.
ISO14443-A
Symbol
Name
Code
Sym0
X
11110011
Sym1
Y
11111111
Sym2
Z
00111111
The ISO14443 -B protocol is implemented with only two symbols. This allows fast addressing with only
one CK pulse.
ISO14443-B
Symbol
Name
Code
Sym0
L
00000000
Sym1
H
11111111
Time Reference Setup
The time reference is defined in the EncoderTimeRef register. The time reference contains the value of
one bit time. Hence Symbol _ Time = 8 * Bit _ Time
The bit time is defined by the EncTimeRef parameter. EncTimeRef is an integer value, it is calculated as
follows:
 Bit _ Time 
 −1
EncTime Re f = 

1
 3.39 Mhz 
EncTimeRef is coded on 5 bits. This means that Bit_Time_max = 9.44µs and Symbol_Time_max =
75.52µs.
3901090121
Rev. 007
Page 12 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
ISO Examples
Norm
Symbol
Bit
EncTimeRef
Time
Time
ISO15693 (1 out of 4)
75.52 µs
9.44 µs
0x1F (11111)
ISO15693 (1 out of 256)
18.88 µs
2.36 µs
0x07 (00111)
ISO14443
9.44 µs
1.18 µs
0x03 (00011)
Symbol Transmission
CK and DIN inputs are used to transmit symbols. On each rising edge of the CK signal, DIN is sampled to
encode the address of the corresponding symbol. This means that each address of the seven available
symbols can be encoded with a maximum of three bits (meaning three CK pulses). To reduce the usage
of the microcontroller for fast protocol, Sym0 and Sym1 can be transmitted with only one bit and, Sym2
and Sym3 with two bits, as shown in the following table.
Symbol
First Symbol
Subsequent Symbols
3 bits are needed to
initiate Transmission
Reduced encoding
possible (minimum 1 bit)
Sym0
000
0
Sym1
001
1
Sym2
010
10
Sym3
011
11
Sym4
100
100
Sym5
101
101
Sym6 (*)
110
110
(*) Symbol 6 is hard coded to 0xFF (11111111).
To initiate a transmission, it is necessary to send the first symbol with three CK pulses to initialize the
communication. On every rising edge of DSYNC, the following symbol is sent. To complete the
transmission, no more CK pulse should be sent after EOF symbol.
3 CK pulses are mandatory
to start transmission
DIN
Sym2
Sym0
Next modulation data
available after the rising
edge of DSYNC
Sym3
No CK pulse to complete
the transmission
Sym5
CK
DSYNC
Modulation
3901090121
Rev. 007
Sym2
Sym0
Page 13 of 26
Sym3
Sym5
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Signal
Assign
MODE
1
RTB
0
DIN
Symbol to transmit
CK
Clock
DOUT
x
DSYNC
Symbol Synchronization
11.3.2. Reception
11.3.2.a. Analog Setup
For a proper reception, the analog chain has to be configured according to the following parameters in the
AnalogConfig register:
•
•
ByPassAll: It bypasses the analog filters in the analog chain. Must be enabled for AM reception.
RSub-carrier: It selects the reception sub-carrier frequency – See table.
RSub-carrier
Sub-carrier
0
423 / 484 kHz
1
847 kHz
ISO Examples
Standard
3901090121
Rev. 007
ByPassAll
RSub-carrier
ISO15693-Single Sub-carrier
1
0
ISO15693-Dual Sub-carrier
0
0
ISO14443-A
1
1
ISO14443-B
0
1
Page 14 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
11.3.2.b. Direct Reception
After analog processing, data reception can be either direct or pre-processed by hardware accelerators,
according to the configuration of the SelDOUT parameter in the DigitalConfig register.
SelDout
Output
Hardware
ISO Standard
00
AM (direct)
--
ISO15693-Single Sub-carrier and ISO14443 - A
01
FM (direct)
--
--
10
FSK (423/484 kHz)
FSK decoder
ISO15693-Dual Sub-carrier
11
PSK (847 kHz)
PSK decoder
ISO14443-B
Note
•
The output phase of PSK decoder is either normal or inverted.
Direct reception is achieved with the following setup.
Signal
Assign
MODE
1
RTB
1
DIN
1
CK
0
DOUT
Received data
DSYNC
x
11.3.2.c. Reception with Majority Voting (MV)
Majority voting allows to:
•
•
•
Filter noisy signal,
Compensate for jitter,
Correct distorted signals.
At the beginning of the time slot (MVTime), an up / down counter is reset. When the input signal is
asserted high, it is counting up and when the input signal is asserted low, it is counting down. At the end
of time slot, the counter value is checked and the output value is set accordingly (low if counter is
negative; high if counter is positive).
Input
signal
Majority
Voting
D1
D2
0 1 0 1 2 1 2 3 0 1 0 -1 -2 -3 -2 -3
MV output
D1
D2
MVTime
Majority Voting Setup
The following parameters in the DigitalConfig register have to be set when using majority voting.
•
•
MVEn: it enables the majority voting function.
DecTimeRef: it defines the duration of the time slot (MVTime)
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Page 15 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
 MVTime 
 −1
DecTime Re f = 

1

 6.78Mhz 
MVTime _ max = 37.76 µs
ISO examples
Norm
MVTime
DecTimeRef
ISO15693 Single Sub-carrier – high baud rate
18.88µs (half bit)
127
ISO15693 Dual Sub-carrier – high baud rate
18.73µs (half bit)
126
ISO15693 Single Sub-carrier – low baud rate
37.6µs
(quarter bit)
255
ISO15693 Dual Sub-carrier – low baud rate
37.46µs (quarter bit)
253
ISO1444-A
4.72µs
(half bit)
31
ISO1444-B
9.44µs
(full bit)
63
Note
•
For Manchester coding, majority voting is on half bit portions only.
In addition, the MVMode parameter in the DigitalConfig register allows giving more weight to low input
levels.
Note
•
It is highly recommended to use Majority Voting for all ISO standard configurations.
MV Reception
To start a reception with majority voting function, assert CK high at the beginning of the response. Then
take data on every falling edge of DSYNC. Reception is stopped by asserting CK low on the last rising
edge of DSYNC. Data output are delayed by DecTimeRef (see next figure).
CK
DSYNC
Input
Signal
D0
D1
D2
D3
DOUT
X
D0
D1
D2
Input
Signal
D3
Majority
Voting
DOUT
3901090121
Rev. 007
Page 16 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Example in ISO1569-Dual Sub-carrier
Input Signal
DOUT
CK
MV start
Standard
Reference for input signal
ISO15693-Single Sub-carrier
Rising edge
ISO15693-Dual Sub-carrier
Rising edge
ISO14443-A
Rising edge
ISO14443-B
Rising / Falling edge
Data Slicer
LTC is an internal signal which controls the time constant of the comparator. This signal is switched to
ensure a proper decoding in ASK modes in order to improve the reading performances.
LTC is controlled according to the following parameters in the LTC register:
•
•
LTCEn: it enables the LTC circuit.
LTCDelay: delay to switch the time constant (see next table).
+
RSSI
Delay
LTC
LTCDelay
Recommended delay for ISO standard
3901090121
Rev. 007
Standard
DelayTime
LTCDelay
ISO15693-Single Sub-carrier
4.72µs
0x1F
ISO14443-A
1.47µs
0x09
Page 17 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Example in ISO15693-Single Sub-carrier
Input Signal
DOUT
CK
MV start
LTC
LTCDelay
11.4. Power Modes
This chip has three power modes. To select one of these modes write the PowerState parameter in the
PowerState register.
PowerState
Power Mode
Symbol
00
Low Power
Idle
01
Transmitter On
Itr
11
Power Down
Istb
Power Down
If the Power Down mode is selected, the crystal oscillator will be turned off. Therefore, it will be impossible
to write the PowerState register to wake up the chip. To wake up the chip, it is necessary to send a falling
edge on CK when DIN is low. During Power Down mode, keep DIN high to avoid glitches on CK.
Wake-up
MODE
CK
DIN
PowerDown
PowerOn
Notes
•
After a wake-up, the chip has to be set in Transmitter On or Low Power mode by updating the
PowerState register, after Tstart.
Low Power
The oscillator is still on but all analog circuitry is off.
3901090121
Rev. 007
Page 18 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
11.5. XBUF Output
The XBUF pin can be used to clock a device or a microcontroller. By default the output is enabled with a
frequency of 6.78MHz. The frequency can be doubled to 13.56MHz by setting the bit XBUFSel. When the
output is not used, it is recommended to disable the clock by setting the bit XBUFEnB.
3901090121
Rev. 007
Page 19 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
12. Configuration Registers
The following tables explain the meaning of the bit configurations in the 13 registers.
Register : AnalogConfig
Address : 0
Bit
Default
Name
Function
7
6
0
XBUFSel
XBUF frequency selection (0 = 6.78MHz, 1 = 13.56MHz )
0
XBUFEnB
XBUF Enable (0= Enabled, 1 = Disabled)
5
0
TModIndex
Transmission Modulation Index (0 = 100%, 1= 10%)
4
0
RSub-carrier
Reception Sub-carrier (0 = 450K , 1 = 847K) – See notes
3
0
Reserved
Do not use – Should always be configured at 0
2
0
ByPassAll
Bypass analog chain (0= Connected, 1 = Bypassed) – See notes
1:0
0
Reserved
Do not use - Should always be configured at 11
Notes
ByPassAll
Demodulation
0
FSK / PSK
1
ASK
RSub-carrier
Sub-carrier frequency
0
423 / 484 kHz
1
847 kHz
Register : PowerState
Address : 1
Bit
Default
Name
Function
7:2
0
Reserved
Do not use
1:0
0
PowerState
Chip Power State – See notes
Notes
Power State [1:0]
3901090121
Rev. 007
Mode
0
0
Idle (oscillator on)
0
1
Transmitter On
1
0
Unused
1
1
Power Down (oscillator off)
Page 20 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Register : Reserved
Address : 2
Bit
Default
Name
Function
7:0
0
Reserved
Do not use
Register : DigitalConfig
Address : 3
Bit
Default
Name
Function
7:6
0
--
Unused
5
0
Reserved
Do not use
4
0
MVMode
Majority Voting Mode (0 = other, 1 = ISO14443A)
3
0
MVEn
Majority Voting Enable (0=Disabled, 1 = Enabled)
2:1
0
SelDout
Reception Output Selection (see table)
0
0
EncoderEn
Hardware Encoder Enable (0=Disabled, 1 = Enabled)
Notes
SelDout
Output
00
AM (DATA): ‘1’ = sub carrier ; ‘0’ = no sub carrier
01
FM (LIMITER): rough digital signal
10
FSK decoded: ‘1’ when f = 423kHz, ‘0’ when f = 484kHz
11
PSK decoded
Register : EncoderSym
Address : 4 to 9
Bit
Default
Name
Function
7:0
0
EncoderSym0
Encoder Symbol 0
7:0
0
EncoderSym1
Encoder Symbol 1
7:0
0
EncoderSym2
Encoder Symbol 2
7:0
0
EncoderSym3
Encoder Symbol 3
7:0
0
EncoderSym4
Encoder Symbol 4
7:0
0
EncoderSym5
Encoder Symbol 5
Notes
•
Symbol 6 is hard-coded to 0xFF (11111111).
3901090121
Rev. 007
Page 21 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
Register : EncoderTimeRef
Address : A
Bit
Default
Name
Function
7:5
4:0
0
--
Unused
0
EncTimeRef
Encoder Time Reference
Register : DecoderTimeRef
Address : B
Bit
Default
7:0
0
Name
Function
DecTimeRef
Decoder Time Reference
Register : LTC
Address : C
Bit
Default
Name
Function
7:6
0
--
Unused
5:1
0
LTCDelay
LTC Delay
0
0
LTCEn
LTC Enable (0=Disabled, 1 = Enabled)
13. Configuration Registers: ISO Configuration Examples
Norm
ISO15693
ASK
Address
Register
ISO14443
FSK
High Baud Rate
High Baud Rate
100% modulation
10% modulation
A
B
0
AnalogConfig
47
63
57
73
1
PowerState*
01
01
01
01
2
Reserved
00
00
00
00
3
DigitalConfig
09
0D
19
0F
4
EncoderSym0
BF
BF
F3
00
5
EncoderSym1
EF
EF
FF
FF
6
EncoderSym2
FB
FB
3F
00
7
EncoderSym3
FE
FE
00
00
8
EncoderSym4
7B
7B
00
00
9
EncoderSym5
DF
DF
00
00
10
EncoderTimeRef
1F
1F
03
03
11
DecoderTimeRef
7F
7E
1F
3F
12
LTC
3F
00
13
00
Notes
•
•
All values are in hexadecimal notation.
Transmitter is switched on.
3901090121
Rev. 007
Page 22 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
14. Standard information regarding manufacturability of Melexis
products with different soldering processes
Our products are classified and qualified regarding soldering technology, solderability and moisture
sensitivity level according to following test methods:
Reflow Soldering SMD’s (Surface Mount Devices)
•
•
IPC/JEDEC J-STD-020
Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices
(classification reflow profiles according to table 5-2)
EIA/JEDEC JESD22-A113
Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing
(reflow profiles according to table 2)
Wave Soldering SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
•
•
EN60749-20
Resistance of plastic- encapsulated SMD’s to combined effect of moisture and soldering heat
EIA/JEDEC JESD22-B106 and EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Iron Soldering THD’s (Through Hole Devices)
•
EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Solderability SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
•
EIA/JEDEC JESD22-B102 and EN60749-21
Solderability
For all soldering technologies deviating from above mentioned standard conditions (regarding peak
temperature, temperature gradient, temperature profile etc) additional classification and qualification tests
have to be agreed upon with Melexis.
The application of Wave Soldering for SMD’s is allowed only after consulting Melexis regarding assurance
of adhesive strength between device and board.
Melexis is contributing to global environmental conservation by promoting lead free solutions. For more
information on qualifications of RoHS compliant products (RoHS = European directive on the Restriction
Of the use of certain Hazardous Substances) please visit the quality page on our website:
http://www.melexis.com/quality.asp.
15. ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
3901090121
Rev. 007
Page 23 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
16. Package Information
The device is packaged in a 20 pin lead free SSOP package.
Pin #
Symbol
Pin Type
Description
1
VDD1
Supply
Transmitter power supply
2
TX
Analog
Output transistor drain connection
3
MOD
Analog
External resistor to set modulation depth
4
VSS1
Supply
Transmitter section ground
RX 20
5
XOUT
Dig-Out
Output of crystal resonator
2 TX
VSS3 19
6
XIN
Dig-In
Input of crystal resonator and external system clock input
3 MOD
RES2 18
7
VSS2
Supply
Digital section ground
4 VSS1
VDD3 17
8
XBUF
Dig-Out
Buffered output of crystal oscillator
5 XOUT
DSYNC 16
9
RES1
Reserved
Should be grounded for normal operation
10
RTB
Dig-In
Receive/Transmit selection
11
DOUT
Dig-Out
Data output
1 VDD1
6 XIN
CK 15
7 VSS2
MODE 14
12
VDD2
Supply
Digital section power supply
8 XBUF
DIN 13
13
DIN
Dig-In
Data input for registers or modulation
9 RES1
VDD2 12
14
MODE
Dig-In
Configuration/Communication selection
10 RTB
DOUT 11
15
CK
Dig-In
Serial clock input
16
DSYNC
Dig-Out
Data synchronization output
17
VDD3
Supply
Receiver section power supply
18
RES2
Reserved
Should be left unconnected for normal operation
19
VSS3
Supply
Receiver section ground
20
RX
Ana-In
Receiver input
Moisture Sensitivity Level is MSL3, according as per IPC/JEDEC J-STD-20.
The mechanical dimensions of this package are depicted on the following page.
3901090121
Rev. 007
Page 24 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
3901090121
Rev. 007
Page 25 of 26
Data Sheet
Jan-2008
MLX90121
13.56MHz RFID Transceiver
17. Disclaimer
Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in
its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the
information set forth herein or regarding the freedom of the described devices from patent infringement.
Melexis reserves the right to change specifications and prices at any time and without notice. Therefore,
prior to designing this product into a system, it is necessary to check with Melexis for current information.
This product is intended for use in normal commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or high reliability applications, such as military,
medical life-support or life-sustaining equipment are specifically not recommended without additional
processing by Melexis for each application.
The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not
be liable to recipient or any third party for any damages, including but not limited to personal injury,
property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or
consequential damages, of any kind, in connection with or arising out of the furnishing, performance or
use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow
out of Melexis’ rendering of technical or other services.
Important notice: The use of Melexis products or software to create products or systems that may
infringe the Intellectual Property rights of third parties is entirely the responsibility of the customer and
Melexis accepts no liability for such infringements.
© 2005 Melexis NV. All rights reserved.
For the latest version of this document, go to our website at:
www.melexis.com
Or for additional information contact Melexis Direct:
Europe and Japan:
Phone: +32 13 67 04 95
E-mail: [email protected]
All other locations:
Phone: +1 603 223 2362
E-mail: [email protected]
ISO/TS 16949 and ISO14001 Certified
3901090121
Rev. 007
Page 26 of 26
Data Sheet
Jan-2008