microID® 125 kHz RFID System Design Guide

1 2004 Microchip Technology 125 kHz RFIDS ystem Design GuideDS51115F-page ii 2004 Microchip Technology contained in this publication regarding deviceapplications and the like is provided only for your convenienceand may be superseded by updates. It is your responsibility toensure that your application meets with your MAKES NO REPRESENTATIONS OR WAR-RANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED,WRITTEN OR ORAL, STATUTORY OR OTHERWISE,RELATED TO THE information , INCLUDING BUT NOTLIMITED TO ITS CONDITION, QUALITY, PERFORMANCE,MERCHANTABILITY OR FITNESS FOR disclaims all liability arising from this information andits use. Use of Microchip s products as critical components inlife support systems is not authorized except with expresswritten approval by Microchip. No licenses are conveyed,implicitly or otherwise, under any Microchip intellectual Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC, and SmartShunt are registered trademarks of Microchip Technology Incorporated in the and other , FilterLab, Migratable Memory, MXDEV, MXLAB, PICMASTER, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the Age, Application Maestro, dsPICDEM, , dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, MPASM, MPLIB, MPLINK, MPSIM, PICkit, PICDEM, , PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, rfLAB, rfPICDEM, Select Mode, Smart Serial.

2 SmartTel and Total Endurance are trademarks of Microchip Technology Incorporated in the and other is a service mark of Microchip Technology Incorporated in the other trademarks mentioned herein are property of their respective companies. 2004, Microchip Technology Incorporated, Printed in the , All Rights Reserved. Printed on recycled received ISO/TS-16949:2002 quality System certification for its worldwide headquarters, Design and wafer fabrication facilities in Chandler and Tempe, Arizona and Mountain View, California in October 2003. The Company s quality System processes and procedures are for its PICmicro 8-bit MCUs, KEELOQ code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip s quality System for the Design and manufacture of development systems is ISO 9001:2000 SHEET MARKINGSM icrochip uses various data sheet markings to designate each document phase as it relates to the product develop-ment stage.

3 The markings appear at the bottom of the data sheet, between the copyright and document and pagenumbers. The definitions for each marking are provided below for your InformationThe information is on products in the Design phase. Your designs should not be finalized with this information as revised information will be published when the product becomes is preliminary information on new products in production but not yet fully characterized. The specifications in these data sheets are subject to change without notice. Before you finalize your Design , please ensure that you have the most current revision of the data sheet by contacting your Microchip sales MarkingInformation contained in the data sheet is on products in full production. 2004 Microchip Technology iiiMPAGEAN680 PASSIVE rfid 2 System Handshake .. 4 Backscatter Modulation .. 4 Data 4 Data Modulation for 125 kHz devices (MCRF2XX).

4 6 Anti-Collision .. 7 MCRF200 DATA SHEET Features .. Electrical Characteristics .. Function RF Configuration Register and Control Logic .. Memory Section .. Examples of Configuration Settings .. Modes Of Operation .. Native Mode .. Read Contactless Programming .. Mechanical Specifications For Die And Wafer .. Failed Die Identification .. Wafer Delivery Notice On Die And Wafer Packaging Package Marking 22 MCRF250 DATA SHEET Electrical Characteristics .. Functional RF Configuration Register and Control Logic .. Memory Section .. Examples of Configuration Settings .. Modes of Native Mode .. Read Contactless Programming .. Anti-Collision .. Mechanical Specifications for Die and Failed Die Identification .. Wafer Delivery Notice on Die and Wafer Handling.

5 Packaging Package Marking 41 Table of ContentsDS51115F-page iv 2004 Microchip Technology CONTACT PROGRAMMING SUPPORT 47 File Specifications .. 47AN710 ANTENNA CIRCUIT Design FOR rfid 49 Review of a Basic Theory for rfid Antenna Design .. 49 Induced Voltage in an Antenna Coil .. 51 Wire Types and Ohmic Losses .. 54 Inductance of Various Antenna Coils .. 57 Configuration of Antenna 67 Consideration on Quality Factor Q and Bandwidth of Tuning Circuit .. 69 Resonant Circuits .. 70 Tuning Method .. 73 Read Range of rfid Devices .. 74 References .. 95 FSK READER REFERENCE Design 97 Reader Transmitting Receiving microID FSK Reader .. FSK Reader FSK Reader Bill of Materials .. FSK Source Code for the PICmicro MCU .. 104 PSK READER REFERENCE Design Reader Transmitting Receiving microID PSK Reader .. PSK Reader PSK Reader Bill of Materials.

6 PSK Source Code for the PICmicro MCU .. 121 ASK READER REFERENCE Design Reader Transmitting Receiving microID ASK Reader .. ASK Reader ASK Reader Bill of Materials .. ASK Reader Source Code for the PICmicro MCU .. 137 Table of Contents (Continued) 2004 Microchip Technology vMPAGEFSK ANTI-COLLISION READER REFERENCE Design Reader Anti-Collision Reader Anti-collision Reader Bill of Materials .. FSK Anti-Collision Source Code for the PICmicro MCU .. 159 USING THE microID PROGRAMMER Programming Signal Waveform .. Power-up, Gap and Verification Programming Calibration of Programming Voltage .. Programming Procedure .. Error Conditions .. Programming Programming in a Standard Terminal Mode .. Programmer Wake-up .. Blank Check .. Program and Verify the Device .. Error Conditions.

7 MicroID Programmer Schematic .. microID Programmer Bill of Materials .. Programmer Source Code for 184 WORLDWIDE SALES AND SERVICE Table of ContentsDS51115F-page vi 2004 Microchip Technology b l e o f C o n t e n t s 2001 Microchip Technology 1AN680 INTRODUCTIONR adio Frequency Identification ( rfid ) systems useradio frequency to identify, locate and track people,assets and animals. Passive rfid systems arecomposed of three components a reader (interroga-tor), passive tag and host computer. The tag is com-posed of an antenna coil and a silicon chip thatincludes basic modulation circuitry and non-volatilememory. The tag is energized by a time-varyingelectromagnetic radio frequency (RF) wave that istransmitted by the reader. This RF signal is called acarrier signal. When the RF field passes through anantenna coil, there is an AC voltage generated acrossthe coil.

8 This voltage is rectified to result in a DC volt-age for the device operation. The device becomesfunctional when the DC voltage reaches a certain information stored in the device is transmitted backto the reader. This is often called backscattering. Bydetecting the backscattering signal, the informationstored in the device can be fully are two classes of rfid device depending ontype of memory cell : (a) read only device and (b) readand write device. The memory cell can be made ofEEPROM or FRAM. EEPROM is based on CMOS sili-con and FRAM is based on ferroelectric CMOS process technology has been matured,the EEPROM can be produced relatively at lower costthan the FRAM device. However, FRAM based rfid device consumes less power which is desirable for lowpower device. Therefore, it is known as a good candi-date for the future rfid device, if its manufacturingcost becomes compatible to that of the CMOS of its simplicity for use, the passive rfid System has been used for many years in various RFremote sensing applications.

9 Specifically in accesscontrol and animal tracking applications. In recent years, there have been dramatic increases inapplication demands. In most cases, each applicationsuses a unique packaging form factor, communicationprotocol, frequency, etc. Because the passive tag isremotely powered by reader s RF signal, it deals withvery small power (~ w). Thus, the read range (com-munication distance between reader and tag) is typi-cally limited within a proximity distance. The read rangevaries with Design parameters such as frequency, RFpower level, reader s receiving sensitivity, size ofantenna, data rate, communication protocol, currentconsumptions of the silicon device, etc. Low frequency bands (125 kHz-400 kHz) were tradi-tionally used in rfid applications. This was because ofthe availability of silicon devices. Typical carrierfrequency (reader s transmitting frequency) in today sapplications range from 125 recent years, the applications with high frequency(4-20 MHz) and microwave ( GHz) bands haverisen with the advent of new silicon devices.

10 Each fre-quency band has advantages and disadvantages. The4-20 MHz frequency bands offer the advantages of low(125 kHz) frequency and microwave ( GHz) , this frequency band becomes the mostdominant frequency band in passive rfid applications. FIGURE 1:SIMPLE CONFIGURATION OF rfid SYSTEMSA uthor:Youbok Lee and Pete SorrellsMicrochip Technology (Interrogator)RF SignalEnergizing/CommandBackscatteringDa ta SignalPassiveRFIDTa gHostComputerRS-232 Passive rfid BasicsmicroID 125 kHz Design GuideDS00680C-page 2 2001 Microchip Technology , INTERROGATORRFID reader is used to activate passive tag with RFenergy and to extract information from the tag. For this function, the reader includes RF transmission,receiving and data decoding sections. In addition, thereader includes a serial communication (RS-232) capa-bility to communicate with the host computer. Depend-ing on the complexity and purpose of applications, thereader s price range can vary from ten dollars to a fewthousand dollar worth of components and packaging.