Rainbow Electronics AT88RF1354 User Manual
1. Features
• Compatible with all ISO/IEC 14443 Type B Compliant Cards,
Tags, and Transponders
• High Performance 13.56 MHz RF Communications Interface
― ISO/IEC 14443-2 Type B Compliant 106 Kbps Signaling
― ISO/IEC 14443-3 Type B Compliant Frame and Data Format
Internal Transmitter Drives Antenna with No External Active
• Circuitry
― Robust Receiver Demodulates and Decodes Type B Signals
• Intelligent RF Reader Functions
― ISO/IEC 14443-3 Type B Polling Function
― Type B Frame Formatting and Decoding is Handled Internally
― Internal CRC Generation and Error Detection
― Adjustable Frame Wait Timing
― Internal Data Buffer
• Two Serial Communication Interface Options
― Two-Wire Interface (TWI) Slave Device with Clock Speed
up to 1 MHz
― SPI Mode 0 Slave Device with Clock Speed up to 2 MHz
― SPI or TWI Mode Selection with Interface Mode Select Pin
• Compatible with 3.3 V and 5 V Microcontrollers
― Supply Voltage: 3.0 to 3.6 Volts or 4.5 to 5.5 Volts
• Package: 6 by 6 mm QFN
• Industrial Operating Temperature: -40° to +85° C
13.56 MHz Type B
RF Reader
Specification
AT88RF1354
Preliminary
2. Description
The AT88RF1354 is a smart, high performance ISO/IEC 14443 Type B RF
Reader IC. The AT88RF1354 communicates with RFID Transponders or
Contactless Smartcards using the industry standard ISO/IEC 14443-2 Type
B signal modulation scheme and ISO/IEC 14443-3 Type B frame format.
Data is exchanged half duplex at a 106k bit per second rate. A two byte
CRC_B provides communication error detection capability.
The AT88RF1354 is compatible with 3.3 V and 5 V host microcontrollers
with two-wire or SPI serial interfaces. In two-wire interface mode the
AT88RF1354 operates as a TWI slave and requires four microcontroller
pins for data communication and handshaking. In SPI interface mode the
AT88RF1354 operates as a mode 0 SPI slave and requires six
microcontroller pins for data communication and handshaking.
To communicate with an RFID transponder the host microcontroller sends a
data packet for transmission over the RF communications channel, and
receives the response data packet that is received from the transponder
over the RF communications channel. AT88RF1354 performs all RF
communication packet formatting, decoding, and communication error
checking. The host microcontroller is not burdened with RF encoding,
timing, or protocol functions since these tasks are all performed by the
AT88RF1354.
8547A• RFID• 10/08
3. Introduction
3.1. Block Diagram
Figure 1. Block Diagram
RFin
C6
ANT
Vss_ANT
Modulator
ANT Driver
Filter
Transmit
Command
and
Response
Logic
Receive
SRAM
Registers
Serial Interface13.56 MHzPLL
ResetBCLKO ISEL Istat SSB SCK SDI SDO ADDRXtal2Xtal1
2 13.56 MHz Type B RF Reader
8547A−RFID−10/08
3.2. System Diagram
Figure 2. Communications in an RFID System
13.56 MHz Type B RF Reader
Host
Microcontroller
3.3. Scope
This AT88RF1354 Specification document contains the electrical and mechanical specifications for the AT88RF1354
RF Reader IC. The AT88RF1354 Command Reference Guide document contains detailed command and register
specifications for the AT88RF1354 RF Reader. The AT88RF1354 Command Reference Guide is a reference for
software developers and embedded systems programmers using the AT88RF1354 Reader.
Reference Designs and additional technical information is available in AT88RF1354 Application Notes. The reference
designs described in the AT88RF1354 Application Notes include schematics, board designs, and a complete bill of
materials. Each reference design has been optimized for reliable, robust communications with cards and tags with
antenna dimensions within a specified size range. See www.atmel.com
3.4. Conventions
ISO/IEC 14443 nomenclature is used in this document where applicable. The following terms and abbreviations are
utilized throughout this document. Additional terms are defined in the section in which they are used, or in
Appendix E.
Card: A Contactless Smart Card or RFID Tag in proximity to the reader antenna.
Host: The microcontroller connected to the serial interface of the reader IC.
PCD: Proximity Coupling Device – is the host and reader with antenna.
PICC: Proximity Integrated Circuit Card – is the tag/card containing an IC and antenna.
Reader: The AT88RF1354 IC with loop antenna and associated circuitry
RFU: Reserved for Future Use – is any feature, memory location, or bit that is held as reserved for future
$ xx: Hexadecimal Number – denotes a hex number “xx” (Most Significant Bit on left).
xxxx b: Binary Number – denotes a binary number “xxxx” (Most Significant Bit on left).
See Atmel Application Note Understanding the Requirements of ISO/IEC 14443 for Type B Proximity Contactless
Identification Cards (doc 2056x) at www.atmel.com
communication protocol.
Se rial Inte rfac e
use by the ISO standards committee or by Atmel.
for detailed information regarding the ISO/IEC 14443 RF
RF Communications
CardReader IC
8547A−RFID−10/08
3
4. Instruction Set
Table 1. Instruction Set Sorted by Command Name
Command Name Description Code
Abort Exit command in progress $0D
Clear Exit command in progress, Clear Buffer, Turn RF OFF $0E
Poll Continuous Poll Continuously for Type B PICCs $02
Poll Single Poll Once for Type B PICCs $01
Read Buffer Read Data Buffer $08
Read Register Read Configuration Register $07
RF OFF Turn off 13.56 MHz RF Field $0B
RF ON Turn on 13.56 MHz RF Field $0A
Sleep Activate standby mode $0C
TX Data Transmit data to PICC and receive the response $03
Write Buffer Write data buffer $09
Write Register Write configuration register $06
All other command code values are not supported
The AT88RF1354 Command Reference Guide document contains all of the detailed information required by a
software developer or embedded systems programmer to use the AT88RF1354 Instruction Set. See www.atmel.com
for the AT88RF1354 Command Reference Guide (doc 5150x).
4.1. RF Communication Commands
The RF ON Command and RF OFF Command are used to enable and disable the 13.56 MHz RF Field transmitter.
The RF Field is turned on at the beginning of a transaction and off at the end, since ISO/IEC 14443 cards and tags
are powered by the RF Field.
The Poll Continuous Command or Poll Single Command is used to search for ISO/IEC 14443 cards in the RF Field
using the standard REQB/WUPB and Slot-MARKER commands. These commands automatically perform the
time-slot polling function described in ISO/IEC 14443 part 3, and return the response from the first card found to the
host microcontroller.
All other RF communication is performed with the TX Data Command. The RF command and data bytes to be
transmitted are sent by the host microcontroller with the TX Data Command to AT88RF1354. The bytes received
from the host are formatted into a Type B standard frame and transmitted on the RF communications channel, along
with the CRC. When a response is received from the card, the response frame is decoded by AT88RF1354 and the
resulting bytes are stored in SRAM buffer memory. If a CRC or frame format error is detected in the response, then
bits are set in the Error Register (EREG). After the entire frame has been decoded by AT88RF1354, the host
microcontroller reads the TX Data Response over the serial interface.
4.2. Reader Configuration Commands
The Read Register Command and Write Register Command are used to read and write the configuration and status
registers of the AT88RF1354. Both the Transmitter Register (TXC) and Receiver Register (RXC) must be configured
before any RF communication occurs.
The Sleep Command is used to put the AT88RF1354 into Standby Mode. In Standby Mode the internal circuitry is
placed in standby, and all internal clocks are stopped.
4 13.56 MHz Type B RF Reader
8547A−RFID−10/08
4.3. Other Commands
The Abort Command can be used to interrupt a Poll Single, Poll Continuous, or TX Data operation that is in progress.
If a Poll Continuous Command is sent but there is no card in the field, then an Abort Command is used to interrupt
the infinite polling loop. All other commands will timeout if no response is received, so it is usually not necessary to
use the Abort Command to interrupt them.
The Clear Command is used to clear the configuration registers and place AT88RF1354 in a known initial state. The
Clear Command is usually the first command sent after the reader is powered on and reset.
The Read Buffer Command and Write Buffer Command can be used to read and write the SRAM buffer that is used
to store RF commands and RF responses. These commands are never required to be used during normal operation
of the AT88RF1354. However, these commands are helpful for testing the integrity of the serial communications
channel during system development.
13.56 MHz Type B RF Reader
8547A−RFID−10/08
5
5. Register Summary
The AT88RF1354 Command Reference Guide document contains all of the detailed information required by a
software developer or embedded systems programmer to use the AT88RF1354 Register Set. See www.atmel.com
for the AT88RF1354 Command Reference Guide (doc 5150x).
Table 2. Register set sorted by address.
Register
Name
CPR0_L $00 (Default) Communication Protocol Register 0 - Low Byte Read-only
CPR0_H $01 (Default) Communication Protocol Register 0 - High Byte Read-only
CPR1_L $02 Communication Protocol Register 1 - Low Byte [RFU] Read / Write
CPR1_H $03 Communication Protocol Register 1 - High Byte Read / Write
CPR2_L $04 Communication Protocol Register 2 - Low Byte [RFU] Read / Write
CPR2_H $05 Communication Protocol Register 2 - High Byte Read / Write
CPR3_L $06 Communication Protocol Register 3 - Low Byte [RFU] Read / Write
CPR3_H $07 Communication Protocol Register 3 - High Byte Read / Write
CPR4_L $08 Communication Protocol Register 4 - Low Byte [RFU] Read / Write
CPR4_H $09 Communication Protocol Register 4 - High Byte Read / Write
SREG $0A Status Register Read-only
EREG $0B Error Register Read-only
IDR $0C Hardware ID Register Read-only
PLL $0D PLL Output Configuration Register Read / Write
TXC $0E Transmitter Register Read / Write
RXC $0F Receiver Register Read / Write
Register
Address
Description Register Type
All other register address values are not supported
6 13.56 MHz Type B RF Reader
8547A−RFID−10/08
13.56 MHz Type B RF Reader
The Register Memory Map in Table 3. shows the field names for each register bit. Read-only registers are colored
yellow. Read/Write registers are colored green. Any bit identified as RFU or Reserved for Future Use is reserved for
future definition by Atmel; these bits must always remain 0 b.
Table 3. Register Memory Map
Register
Name
CPR0_L $00 Reserved for future use
CPR0_H $01 FWI RFU
CPR1_L $02 Reserved for future use
CPR1_H $03 FWI RFU
CPR2_L $04 Reserved for future use
CPR2_H $05 FWI RFU
CPR3_L $06 Reserved for future use
CPR3_H $07 FWI RFU
CPR4_L $08 Reserved for future use
CPR4_H $09 FWI RFU
SREG $0A RF POR CD RFU
EREG $0B CRC FRAME BYTE TIME COL SPE RFU
IDR $0C ID
PLL $0D SL! SL0 ENB RFU RS1 RS0
TXC $0E TXP ML
RXC $0F G SS
Register
Address
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
All other register address values are not supported
Description
5.1. Communications Protocol Registers
AT88RF1354 contains five 16 bit Communication Protocol Registers for configuration of the RF communication
protocol. Each register contains a high byte (CPRx_H) and a low byte (CPRx_L). The CPRx_H registers are used to
configure the Frame Wait Time. The CPRx_L registers are currently unused (Reserved for Future Use) and must
remain set to $00.
CPR0 is a read-only register containing the default ISO/IEC 14443 communication protocol settings. The Poll Single
and Poll Continuous Commands always use CPR0 to configure the RF channel during polling.
CPR1, CPR2, CPR3, and CPR4 are available for configuration of RF channel for the TX Data Command. Each TX
Data Command contains a field that selects the CPR register to be used, so frame wait time is independently
configured on each command. If different timeout settings are written to each CPRx register, then the application
developer can use an appropriate timeout for each TX Data Command sent, minimizing the time required to recover
when no response is received on the RF communication channel.
7
8547A−RFID−10/08
5.2. Status Registers
AT88RF1354 contains three read-only registers that provide status information. The operational status of the IC is
contained in the SREG Register; by reading this register it can be determined if the RF Field is on and if the analog
circuits are fully powered up. The RF communication errors flags are stored in EREG; these flags are also returned in
the response of RF communication commands.
The IDR Register contains the hardware ID revision of the die; all die manufactured with the same design contain
identical IDR Register values. If the die design is changed, then IDR is updated.
5.3. Configuration Registers
Three registers control the configuration of the receiver, transmitter, and CLKO pin. The gain and noise immunity of
the receiver is controlled by the RXC Register. The transmit power and modulation index are controlled by the TXC
Register. The PLL Register controls the CLKO pin frequency, the CLKO output enable, and standby mode control
bits.
8 13.56 MHz Type B RF Reader
8547A−RFID−10/08
6. Pin List
Pin Name Description Type
1 VCC_ANT Power for Transmitter and Antenna Drive Circuits Power
2 VSS_ANT Ground for Transmitter and Antenna Drive Circuits Ground
3 ANT Antenna Driver Output
4 Xtal1 Crystal Pin 1
5 Xtal2 Crystal Pin 2
6 C5 Bypass Capacitance Output
7 Test1 VSS by Customer TEST input
8 CLKO Programmable Clock Output from PLL Output
9 ResetB Reset Bar from Microcontroller Input
10 ISEL Select Serial Interface Mode (SPI or TWI) Input
11 TestD No Connect by customer I/O
12 Istat Serial Interface Status (Handshaking Signal) Output
13 SSB SPI Interface "Slave Select" Input
14 SCK Serial Data Clock (SPI and TWI) Input
15 SDI SPI Serial Data Input or TWI Serial Data Input/Output I/O
16 Test2 VSS by Customer TEST input
17 Test3 VSS by Customer TEST input
18 N.C. Not Used
19 SDO SPI Serial Data Output Output
20 ADDR TWI Device Address Select Input
21 C1 Bypass Capacitance Output
22 VSS Ground Power
23 VSSA Ground Power
24 VCC Power for I/O Buffers, digital and analog circuits Power
25 C4 Bypass Capacitance Output
26 C2 Bypass Capacitance Output
27 C3 Bypass Capacitance Output
28 N.C. Not used
29 C7 Bypass Capacitance Output
30 N.C. Not used
31 TestR No Connect by customer Analog Out
32 RFin Input to RF receiver Input
33 N.C. Not used
34 Rmod VSS _ANT by customer Analog TEST
35 C6 Bypass Capacitance Output
36 N.C. Not used
13.56 MHz Type B RF Reader
Xtal Buffer
8547A−RFID−10/08
9
6.1. Power and Ground Pin Descriptions
6.1.1. V
[24]
CC
Supply Voltage for I/O buffers, digital, and analog circuits. VCC voltage must match the microcontroller I/O voltage
since all digital I/O levels are referenced to V
CC
Two VCC bypass capacitors must be connected between the VCC pin and VSS. A 15 nF capacitor with SRF of 32 MHz
must be placed within 3 mm of the package. A 2.2 uF capacitor should also be placed within 3 cm of the package.
Ceramic capacitors with X5R or X7R dielectric and a working voltage of 10 volts minimum should be used.
6.1.2. VSS [22]
Digital ground. Ground for I/O buffers and digital circuits. For maximum performance the digital ground plane must be
separated from the analog ground plane (V
A) and the antenna ground plane (VSS_ANT) by a minimum of 20 mils.
SS
6.1.3. VSSA [23]
Analog ground. Ground for analog circuits. For maximum performance the VSSA ground plane should connect to the
V
ground plane at only a single point within 1 cm of pins 22 and 23. VSSA should not be connected directly to
SS
V
_ANT.
SS
6.1.4. VCC_ANT [1]
Antenna supply voltage. Powers the transmitter and antenna drive circuits.
Two V
SRF of 32 MHz must be placed within 3 mm of the package and a 2.2 uF capacitor must be placed within 5 mm
_ANT bypass capacitors must be connected between the VCC_ANT pin and VSS_ANT. A 15 nF capacitor with
CC
of the package. Ceramic capacitors with X5R or X7R dielectric and a working voltage of 10 volts minimum should be
used.
6.1.5. VSS_ANT [2]
Antenna ground. High current return path for transmitter and antenna drive circuit current. For maximum performance
the V
_ANT ground plane should connect to VSS at only a single point near the power filters at the edge of the reader
SS
circuit block.
6.1.6. QFN Package Thermal Pad [ePad]
Ground for the die substrate. Must be connected directly to the VSS digital ground plane with multiple vias. The
package thermal pad must be soldered to a thermal pad on the board as described in Appendix D to dissipate heat
generated in the die.
Warning: If V
10 13.56 MHz Type B RF Reader
8547A−RFID−10/08
, VSSA, VSS_ANT, and ePad are tied to a single monolithic ground plane, then transmitter noise will be
SS
injected into the receiver circuit. Likewise, if VCC and VCC_ANT are tied to one monolithic power plane,
then transmitter noise will be injected into the receiver circuit. These PCB configurations will significantly
reduce the communication performance of the reader (reducing the communication distance).
6.2. Digital Pin Descriptions
6.2.1. ADDR [20]
TWI device address select input pin. Selects between two TWI device addresses as shown in Table 4. In SPI
communication mode this pin should be connected to Vss.
Table 4. TWI Device Address
ADDR Pin
VSS 0 1 0 1 0 0 0 $51 $50
VCC 1 1 0 1 0 1 0 $D5 $D4
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
6.2.2. CLK0 [8]
Clock Out pin. The PLL register selects the frequency of the clock which is output on this pin for use by external
circuits. The default CLKO frequency is 1.978 MHz. If the clock is not needed, then the CLKO output should be
disabled by programming the ENB bit of the PLL register to one.
13.56 MHz Type B RF Reader
TWI Device Address
All other values are NOT supported
TWI_R TWI_W
Table 5. CLKO Output Frequency Options
Bit 1 Bit 0 CLKo Frequency
0 0 1.978 MHz
0 1 3.955 MHz
1 0 7.910 MHz
1 1 15.82 MHz
6.2.3. ISEL [10]
Interface Select input pin. Selects TWI communications when low. SPI communication mode 0 is selected when high.
6.2.4. Istat [12]
Interface Status output pin. Istat is the serial interface handshaking signal. A high level on Istat indicates that a byte
of data is ready to read from the serial interface port. A low level on Istat indicates that the serial interface buffer is
empty.
Note: Use of Istat for serial communications control is mandatory, and the AT88RF1354 will not accept commands
from the host microcontroller when Istat is high.
6.2.5. ResetB [9]
Reset Bar input pin. A low on ResetB causes the device to reset. ResetB must be pulled high by the host
microcontroller and/or by an external resistor to V
when the device is in use.
CC
6.2.6. SCK [14]
Serial Clock input pin. In both SPI and TWI serial communication modes this pin is used as the serial interface clock.
8547A−RFID−10/08
11
6.2.7. SDI [15]
Serial Data In pin. In SPI communication mode this pin functions as the serial data input. In TWI communication
mode this pin functions as the serial data I/O.
6.2.8. SDO [19]
Serial Data Out pin. In SPI communication mode this pin functions as the serial data output. In TWI communication
mode this pin is not used.
6.2.9. SSB [13]
SPI Slave Select Bar input pin. In SPI communication mode this pin functions as the slave select input. In TWI
communication mode this pin is not used and should be connected to V
6.3. RF Pin Descriptions
6.3.1. ANT [3]
Antenna driver. The 13.56 MHz carrier frequency is generated by ANT and is shaped into a sine wave by external
passive circuitry.
6.3.2. C6 [35]
C6 Antenna bypass capacitor pin. The C6 pin provides power to the antenna circuits and modulates the power level
for communications.
.
SS
6.3.3. RFin [32]
RF input pin. RFin is the input to the receiver. A resistor/capacitor filter is used to limit the peak to peak voltage on
this pin to a safe level. See the AT88RF1354 reference design for appropriate component values.
6.4. Analog Pin Descriptions
6.4.1. C1 [21]
C1 bypass capacitor pin. Bypass capacitance of 0.33 uF for the digital circuits must be connected between the C1 pin
and V
. This capacitor must be placed within 3 mm of the package. Any 0.33 uF ceramic capacitor with X5R or X7R
SS
dielectric and a working voltage of 10 volts minimum may be used.
6.4.2. C2 [26]
C2 bypass capacitor pin. Bypass capacitance of 47 nF for the analog circuits must be connected between the C2 pin
and V
A. This capacitor must be placed within 3 mm of the package. Any 47 nF ceramic capacitor with X5R or X7R
SS
dielectric and a working voltage of 10 volts minimum may be used.
6.4.3. C3 [27]
C3 bypass capacitor pin. Bypass capacitance of 47 nF for the analog circuits must be connected between the C3 pin
and V
A. This capacitor must be placed within 3 mm of the package. Any 47 nF ceramic capacitor with X5R or X7R
SS
dielectric and a working voltage of 10 volts minimum may be used.
6.4.4. C4 [25]
C4 bypass capacitor pin. Bypass capacitance of 0.33 uF for the analog circuits must be connected between the C4
pin and V
X7R dielectric and a working voltage of 10 volts minimum may be used.
A. This capacitor must be placed within 3 mm of the package. Any 0.33 uF ceramic capacitor with X5R or
SS
12 13.56 MHz Type B RF Reader
8547A−RFID−10/08
6.4.5. C5 [6]
C5 bypass capacitor pin. Bypass capacitance of 0.33 uF for the digital circuits must be connected between the C5 pin
and VSS. This capacitor must be placed within 3 mm of the package. Any 0.33 uF ceramic capacitor with X5R or X7R
dielectric and a working voltage of 10 volts minimum may be used.
6.4.6. C7 [29]
C7 bypass capacitor pin. Bypass capacitance of 47 nF for the analog circuits must be connected between the C7 pin
and VSSA. This capacitor must be placed within 3 mm of the package. Any 47 nF ceramic capacitor with X5R or X7R
dielectric and a working voltage of 10 volts minimum may be used.
6.4.7. Xtal1 [4]
Crystal pin 1. A 13.56 MHz crystal must be connected between Xtal1 and Xtal2.
6.4.8. Xtal2 [5]
Crystal pin 2. A 13.56 MHz crystal must be connected between Xtal1 and Xtal2.
6.5. Test Pin Descriptions
6.5.1. Test1 [7]
Test input pin 1. This pin must be connected to VSS on the board to prevent the IC from entering test mode.
13.56 MHz Type B RF Reader
6.5.2. Test2 [16]
Test input pin 2. This pin must be connected to VSS on the board to prevent the IC from entering test mode.
6.5.3. Test3 [17]
Test input pin 3. This pin must be connected to VSS on the board to prevent the IC from entering test mode.
6.5.4. TestD [11]
Test output pin D. This test output must be left open by the user.
6.5.5. TestR [31]
Test output pin R. This test output must be left open by the user.
6.5.6. Rmod [34]
Test pin Rmod. This pin must be connected to VSS _Ant on the board.
6.6. Other Pins
6.6.1. N.C. [18, 28, 30, 33, 36]
No Connect pins. These package pins are not used and can be left open by the user.
8547A−RFID−10/08
13
7. Typical Application
7.1. Operating Principle
Contactless RF smart cards operating at 13.56 Mhz are powered by and communicate with the reader via inductive
coupling of the reader antenna to the card antenna. The two loop antennas effectively form a transformer.
An alternating magnetic field is produced by sinusoidal current flowing thru the reader antenna loop. When the card
enters the alternating magnetic field, an alternating current (AC) is induced in the card loop antenna. The PICC
integrated circuit contains a rectifier and power regulator to convert the AC to direct current (DC) to power the
integrated circuit.
The reader amplitude modulates the RF field to send information to the card. The PICC contains a demodulator to
convert the amplitude modulation to digital signals. The data from the reader is clocked in, decoded and processed
by the integrated circuit.
The card communicates with the reader by modulating the load on the card antenna, which also modulates the load
on reader antenna. ISO/IEC 14443 PICCs use a 847.5 khz subcarrier for load modulation, which allows the reader to
filter the subcarrier frequency off of the reader antenna and decode the data.
Figure 3. The card antenna and reader antenna effectively form a transformer
IC
READER
14 13.56 MHz Type B RF Reader
8547A−RFID−10/08
7.2. Application
In a typical application the AT88RF1354 reader circuitry and the loop antenna are integrated on a single four layer
printed circuit board. The host microcontroller and power supply may reside on the same PCB, or on a separate PCB
depending on the application requirements.
The passive components required for the reader IC to function are placed in a small area immediately surrounding
the QFN package for optimum RF circuit performance. The PCB loop antenna is placed a minimum of 1 inch away
from all other metal, including the reader circuit ground and power planes, to minimize distortion of the magnetic field
which reduces RF communication performance. A typical loop antenna is designed for an inductance of 800 to 1600
nanohenries, DC resistance of 0.1 to 0.3 ohms, low parasitic capacitance, and includes a matching electric field
shield.
Whether the power supply and microcontroller are integrated in the same board or are on a different board, power
filtering is included at the edge of the reader circuit ground and power planes to isolate the reader from in-band
system noise and to protect the host microcontroller from reader generated noise. The reader ground and power
planes must be isolated from the balance of the system to prevent current loops from forming which will interfere with
RF tag performance.
Layout of both the reader circuitry and loop antenna are critical, and are beyond the scope of this document. See the
reference designs in the AT88RF1354 Application Notes for layout and circuit recommendations.
Figure 4. Typical AT88RF1354 Reader board layout
13.56 MHz Type B RF Reader
Power Supply
Microcontroller
Circuit
Reader
Circuit
Loop
Antenna
8547A−RFID−10/08
15
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