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Datasheet: MLX90121 (Melexis, Inc.)

13.56MHz Rfid Transceiver

 

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MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
Page
1
Oct/02
Rev. 003
Features
Up to 200mW output power
3.3V and 5V supply
Complies with ISO 15693-2
Complies with ISO 14443-2 A
Low external component count
Short to mid range applications
High performance at minimum system cost
Applications
Any domain from Freight tracking systems, to Access control.
Proximity Smart card base station reader
ISO15693 up to 20cm with smart card size inlays.
Custom protocol 13.56MHz read/write base stations
Ordering Information
Part
No.
Temperature
suffix Package
code
MLX90121
C (0C to 70C)
FR (SSOP 20)
MLX90121
E
(-40C
to
85C)
FR
(SSOP
20)
Description
The MLX90121 is an ISO compliant smart labels and
smart cards reader circuit. Applications range from
freight identification systems to access control.
The main features include user selectable
modulation depth in write mode, whereas single sub
carrier AM or FSK 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 sub carrier AM detection,
ensuring fast and clean data recovery. The limiting
output of the log amp is used for FSK recovery.
The transmitter uses a built in open drain output
transistor, which can provide up to 200 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 readers
applications. An external transistor may be used to
boost the RF power level and achieve a greater
reading range.
The digital interface provides data to be processed
by a micro-controller. The chip is configured with a
shift register. Communication with the circuit is
achieved by means of a serial link.
Functional Diagram
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
Page
2
Oct/02
Rev. 003
Table of contents
1. Electrical Specifications........................................................................3
2. Absolute Maximum Ratings..................................................................6
3. Functional Description.........................................................................7
4. Typical Communication........................................................................8
5. Recommended application schematic....................................................8
6. Register Configuration.........................................................................9
7. Reliability Information..........................................................................10
8. ESD Precautions..................................................................................10
9. Packaging Information ........................................................................10
10. Disclaimer..........................................................................................13
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
Page
3
Oct/02
Rev. 003
1. Electrical Specifications
T
A
= -40
o
C to 85
o
C, V
DD
= 5V (unless otherwise specified)
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
General DC Parameters
Operating supply voltage range
VDD
3
5
5.5
V
A
Supply ripple
See note 0
40
mVpp
-
Standby current consumption (Istb)
Istb
VDD =5.5 V
1
50
uA
A
Idle mode current consumption (Idle1)
(Analog section off)
IDDQ1
External clock, VDD=5.5 V
12
15
mA
C
Idle mode current consumption (Idle2)
(Analog section off)
IDDQ2
On board resonator, VDD=5.5V
3
7
11
mA
A
Operating current (Iop)
IDD
9
14
19
mA
A
Transmit current (Itr)
ITX
80
100
120
mA
C
Transmitter specifications
Max peak voltage applied on drain of output
transistor
32
V
D
Maximum output transistor power dissipation
500
mW
D
Output transistor ON resistance
Id = 50 mA
2
5
A
Output power for five volts operation
See note 1
180
200
mW
D
Amplitude modulation depth adjustment range in
10% mode.
External resistor connected between
MOD pin and ground, See note 1
0
90 % D
Amplitude modulation depth in 10% mode
With nominal external resistor (12W),
See note 1
10 12 16 %
D
Minimum depth for 100% ASK
See note 1
40
dB
D
Rise and fall time for 100% ASK
See note 1
2.5
4
s
D
Rise and fall time for 10% modulation depth
With nominal external resistor (12W),
See note 1
1
1.5
s
D
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
Page
4
Oct/02
Rev. 003
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Receiver specifications
Small signal input impedance (RX)
50
100
200
k
D
Input RF voltage range (RX VSS)
With 1 k series external resistor
1
1.8 - 4.9
Vdd
V
D
Receiver sensitivity (FSK)
See note 2
-40
-65
dBm
C
Baseband receiver sensitivity (FSK)
See note 3
-40
-65
dBm
A
FSK IF filter cut off points
130
200-
1400
1800
kHz A
Total gain, in FSK mode
100 120 140 dB
C
Log amplifier section
Limiting gain
70
80
dB
D
Sensitivity for AM recovery
-40
-55
A
Sensitivity for FM recovery
-40
-65
dBm
A
RSSI Analog output
Driving capability
5pF //
200 k
D
External current source
1
3
mA
D
Internal current source
25
50
90
uA
D
Serial Link and digital I/O
Output voltage low
Vol
Iolmax=1mA
0
0.2
0.4
V
A
Output voltage high
Voh
4.6
4.8
5
V
A
Output current drive
Iol
Vol
0.4 Volt
1
mA
A
Input voltage high
Vih
0.7 Vdd
Vdd + 0.3 V
A
Input voltage low
Vil
-0.3
0.3 Vdd
V
A
Maximum CK frequency
MHz
D
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
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Oct/02
Rev. 003
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Crystal Oscillator
Frequency range (Fxtal)
4
13.56 16
MHz
D
Start-up time (Tstart)
2
5
ms
D
Xtal series resistance
50
100
D
External clock signal specifications
see note 4
Min sine wave amplitude AC coupled
Input on pin XIN
1
Vdd Vpp
C
Min sine wave amplitude, DC coupled
Input on pin XIN
Input has to be centered around
Vdd/2
1
Vdd
Vpp
C
XBUF output specifications
XBUF Low Level (Col)
Sink current = 1mA
0
0.2
0.4
V
A
XBUF High Level (Coh)
Sink current = 1mA
4.6
4.8
5
V
A
Rise and fall times (10%-90%)
1k load resistor //12pF
3
ns
D
Notes:
Parameter categories: A means 100% production tested, C means correlation tested (parameters whose values can be
inferred from other measurements, but are pertinent as a design aid to the end user), D means guaranteed by design.
0) The maximum ripple can create a reduction of the reading distance in order of 10%. Frequency: 0 to 15MHz.
1) Parameter measured using recommended output matching network.
2) This parameter is specified with the chip wired as specified in the typical application circuit provided below, with the
transmitter switched on. It cannot be measured during the final test.
3) This parameter is measured at base band for all specified modulation modes. The measurement is made at
RSSI output with the input diode detector bypassed.
4) 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%.
Fig 2: chip talks
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
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Oct/02
Rev. 003
Fig 3: Block diagram
2. Absolute maximum ratings
Parameter
Symbol Condition
Min
Max
Unit
Supply voltage (Vdd with respect to Vss)
Vdd
DC
-0.3
6
V
Input voltage on any pin (except TX_OUT)
Vin
-0.3
VDD+0.3 V
Maximum power dissipation
Pmax
500
mW
Maximum junction temperature
Tj
+150
C
Storage temperature
Tstor
-55
+150
C
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
Page
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Oct/02
Rev. 003
3. Functional description
Power supply
The 90121 requires a nominal 5 volts external power
supply. Operation is guaranteed between 3 Volts
and 5.5 Volts, with reduced output power between 3
Volts and 5 volts. The current drain depends on the
antenna impedance and the output matching
network configuration. 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 the latter case, the general performance
and harmonic suppression will be reduced.

100 % modulation is achieved by switching the
output transistor, while MOD is connected to ground.
10% modulation is realized by adding an external
resistor (12Ohm) between MOD and VSS1.
Modulation is realized by a second low ohmic
MOSFET which shorts this external resistor.
The external resistor provides the default modulation
depth setting. It is possible to increase this resistor to
further 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 recovery
The demodulated input signal is amplified and band
pass filtered. The filter has a typical bandwidth of
200 to 1400 kHz. The total gain of the IF filter strip is
about 40dB. The signal is then hard limited by a 80
dB amplifier, and fed to the comparator.
ASK recovery
For ASK recovery, the high pass sections of the
filters are bypassed, to avoid falling edge
degradation by the filter settling time. The signal is
essentially DC coupled and fed to the input of the
amplifier. The amplifier also serves as envelope
detector. The demodulated output is then fed to the
comparator.

Reference clock and internal oscillator
The reference clock has to be applied to the XTAL1
pin. A sine wave centered at VCC/2 or a CMOS
logic compatible signal are acceptable external
system clocks. 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, but the oscillator may work at any
frequency from 4 MHz to 16 MHz.
Reset defaults and power management
After a power on reset has been performed, the
device is placed in its default configuration. There
are three available power modes:
-
In the first mode, the device is fully powered.
-
In the idle mode, only the reference oscillator
and a minimal set of associated circuitry are
running.
-
In the power down mode, the device internal
bias system is completely switched off.

Serial communication interface
The communication interface normally uses four
wires:
-
CK, serial clock for register data. Input with anti-
glitches.
-
DIN, data input for register or modulation
-
DOUT, data output
-
Mode, selection between register and
modulation
-
LTC, Low Time Constant: used to change the
time constant in the comparator (AM)
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
Page
8
Oct/02
Rev. 003
4. Typical Communication
When Mode is at `0', the data are shifted in a temporary shift register. At the rising edge of Mode,
these data are loaded in the configuration register. Then DIN served to modulate the carrier.
5. Recommended application schematic
This schematic has been optimized to drive a fifty ohms resistive antenna, using a five volts power
supply.
Remarks:
-
The pin LTC has an internal pull-down resistor and can be left floating in most practical cases
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
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Oct/02
Rev. 003
6. Register Configuration
At start up, all bits are at `0'.
# Bit
Purpose
Binary MSB first (Hex)
0
To bypass all the filters and gain blocks
- AM : 1
- FSK : 0
1-7 Test
Normal use = 0
8-9 Comparator Threshold
Normal use = 10 (0x2)
10
To reduce the voltage drop of the detector
VDD= 5V : 0
VDD= 3.3V: 1
11
To reduce the baud rate (AM only)
26kbaud = 0
6.6kbaud = 1
12
To use a subcarrier at 847kHz
AM, ISO 14443 = 1
Else =0
13
Modulation depth
10% : 1
100% : 0
14-16 Power Management
Carrier On : 001 (0x1)
Low Power : 010 (0x2)
Power down: 100 (0x4)
17-24 Test
Normal use = 0
25-26 Select DOUT
AM : 00 (0x0)
FSK : 10 (0x2):
- output = 1 when fsubc = 423kHz
- output = 0 when fsubc = 484kHz
27
Select XBUF, buffered output clock speed
13.56MHz : 1
6.78MHz : 0
Example settings (MSB first)
AM, VDD=5V, High Baudrate, 15693, 100%,
0000 0000 0000 0110 0010 0000 0001
FSK VDD=5V, High Baudrate, 15693, 100%,
0101 0000 0000 0110 0010 0000 0000
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
Page
10
Rev. 003
7. Reliability Information
Our devices are classified and qualified regarding their suitability for infrared, vapor phase and wave soldering
with usual SnPb-lot (melting point at 183degC).
The following test methods are applied:
-
IPC/JEDEC J-STD-020A (issue April 1999)
Moisture/Reflow Sensitivity Classification For Non-hermetic Solid State Surface Mount Devices
-
CECC00802 (issue 1994)
Standard Method For The Specification of Surface Mounting Components (SMDs) of Assessed Quality
-
MIL 883 Method 2003 / JEDEC-STD-22 Test Method B102
Solderability

The application of Wave Soldering for SMDs is allowed only after consulting Melexis regarding assurance of
adhesive strength between device and board.

For all soldering technologies deviating from a.m. standard conditions (regarding peak temperature,
temperature gradient, temperature profile etc) additional classification and qualification tests have to be agreed
upon with Melexis.

For more information on manufacturability/solderability see quality page at our website:
http://www.melexis.com/
8. ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products
9. Packaging Information
See following pages for the SSOP20 outline.
PINOUT
Nr Name Description
1 VDD1 Output stage supply
2 TX
Output stage drain (Transmitter)
3 MOD Modulation
resistor
4 VSS1 Output
stage
ground
5 XOUT Crystal
output
6 XIN Crystal
input
7 VSS2 Digital
ground
8 XBUF Crystal
buffered
output
9 LTC
AM time constant switch input
10 TEST Test input: ground for normal
operation.
Nr Name Description
11 DOUT Data
output
12 VDD2 Supply
connection
13 DIN Data
input
14 MODE Selection of DIN input: register or
modulation
15 CK
Serial clock for register data
16 RSSI
FM, AM or RSSI signal output
17 VDD3
Input stage supply
18 n.c.
Not connected, leave floating for
normal use
19 VSS3
Input stage ground
20 RX
Input stage (Receiver)
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
Page
11
Rev. 003
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
3901090121
Page
12
Rev. 003
MLX90121
MLX90121
MLX90121
MLX90121
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver
13.56MHz RFID Transceiver



3901090121
Page
13
Rev. 003
10. 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.
2002 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:
All other locations:
Phone: +32 13 67 04 95
Phone: +1 603 223 2362
E-mail: sales_europe@melexis.com
E-mail: sales_usa@melexis.com
QS9000, VDA6.1 and ISO14001 Certified
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