MLX90111 128bit Read Write Transponder Features - 144bit EEPROM code, flexible Read Write Transponder IC Very Big reading range, and large write range. ID configured as 8 user words of 16 bits, and multiple write protection levels, including OTP 16 bit Configuration word with lock flags per word and option bits Different encoding and datarate options 250pF integrated tuning capacitance with wide post assembly tuning range 100,000 write cycle, 10 year EEPROM retention Guaranteed data integrity for reliable programming Applications Animal ID (ISO 11784, -85 compliant), ATM, Access Control, Material Logistics, Overmoulded assemblies with important detuning effects. Ordering Information Part No. MLX90111 Temperature Range 25 °C Consumer -40 to 85 °C Automotive Package Sawed wafer on frame Bare die in blistertape SOIC-8 150mils Production parts available Q1 2001 Functional Diagram MLX90111 Coil L Ctune GND MLX90111 128bit Read Write Transponder Description The MLX90111 is a flexible 128 bit Read Write Transponder IC operating at 125kHz. It has been designed for high performant and highly reliable RFID systems requiring multiple write access to the transponder memory. Clock and power supply are taken from the electromagnetic field. A resistor is switched in parallel to the resonant circuit formed by the integrated tuning capacitor and the external coil, to amplitude modulate the electromagnetic field. Encoding of the 128 bits ID and data rate can be defined by setting the corresponding EEPROM bits. High quality factors can be applied as the frequency can be tuned over a range of +/-10% to +/-0.5% accurate after assembly, by changing the value of the tuning capacitor up to +/- 2pF. The EEPROM is configured as 11 words of 16 bits. Words 1 to 8 form the ID and are continuously read out during normal operation. Each of these can be individually locked, or the complete EEPROM can be set to read only. The transponder can be written over the full range from 0% to 60% of the normal reading distance. The transponder stops modulating when receiving an AM asynchronous pattern. It will then synchronize on the first bit it receives. The 32 bit write command is transmitted using Return to One modulation, including direct word addressing and multiple security checks. Data integrity is guaranteed by critical read out after programming. Page 1 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder MLX90111 Electrical Specifications Operating Parameters are based on test set up (see Schematic below). Toper = -40°C to 85°C, Operating frequency = 120kHz (unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units Regulated supply voltage VDD (3) 3.0 Power On Level VPOR Continuous normal reading of the ID 1.55 1.8 Sensitivity level (e.m.f.) Vacsens Continuous normal reading of the ID 200 170 Weak power: Vacmin = 200mVpp 0.2 4 V(4) Medium power: Vac = 5Vpp 2.8 7.5 V(4) 5 10 V(4) Modulation Depth ASK High power: Vac = 20Vpp EEPROM writing supply voltage Vacee EEPROM writing supply current Iee ACP modulation depth Critical reading ID Vachigh=Vacee EEPROM data retention Tret Critical reading ID 10 EEPROM write cycles Ncycle Critical reading ID 100k 4.0 V 2.2 V mV 1 V 10 µA 20 % (5) year cycles Coil-GND tune capacitor Toper=25oC 200 pF(6) Total Tuning range Toper=25oC, 5bits 124 pF(6) Tuning accuracy Toper=25oC, LSB/2 2.0 pF(6) DC input current clamping IclampLow VdutDC = +/- 2V 40 IclampHigh VdutDC = +/- 10V 1 3.5 1000 NA 10 mA Notes: Note (1): Specifications are tested 100% or guaranteed by characterization. Note (2): All specifications are valid for Manchester and Biphase encoding, and for 2kbaud and 4kbaud data rate options. 50 Vin Vac L=6.8mH Cpar=10pF Qrc @ 120KHz=48.8 C1+C2=250pF Vdut COIL C1 C2 90111 DUT GND Note (3): Maximum supply voltage is generated by forcing 10mA between coil and ground pin. Note (4): Min = Vbottom (modulation on), Max = Vtop (modulation off). Note (5): Modulation depth is calculated as Vachigh -Vaclow / Vachigh + Vaclow. Lower modulation depths may be applied, but the performance of the system may vary along the distance between reader and transponder coil. Higher modulation levels will reduce the maximum Write distance. Note (6): Lot to lot spread on capacitance is 20%. Temperature shift is typically 0% on -40°C, and +1% at 85°C. MLX90111 128bit Read Write Transponder Page 2 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Block diagram RF Limiter Trimming Ctune Modulator COIL M O D VDD VDD Cbuffer TCKIN POR TEST SPEED CLOCK RECOVERY DATAIO Digital Controller CLOCK ADDR DEMODUL. SUPPLY VSS [mA] DATA EEPROM DATA VDD MLX90111 clamping (DC) 15 10 5 [V] 0 -20 -10 0 10 20 -5 -10 -15 MLX90111 128bit Read Write Transponder Page 3 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder COMMAND FUNCTION ADDRESS EEPROM memory maps BITPOSITION (MSB first) F E D C B A 9 8 7 6 5 4 3 2 1 0 1 CONTINUOUS 4 CMF1 3 ID 2 WPW Read memory map 0 5 6 7 C Tune+CFG CMF1 0 T4 T3 T2 T1 T0 0 0 0 0 0 0 0 0 CODE SPEED COMMAND WPW(FLAGS) FUNCTION Lock word: "01010101" ADDRESS B BITPOSITION (MSB first) F E D C B A 9 8 7 6 5 4 3 2 1 0 0 CMF1 4 CMF2 3 ID 2 WPW Write memory map 1 5 6 7 9 CMF2 0 T4 T3 T2 T1 T0 0 0 0 0 0 0 0 0 0 0 A CMF2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CODE SPEED WPW(FLAGS) Tune Lock word: "01010101" CFG 8 MLX90111 128bit Read Write Transponder Page 4 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder General Description Demodulator The MLX90111 is a 128bit Read Write transponder IC. The integrated tune capacitance and the external coil form a resonant LC antenna that absorbs part of the electromagnetic energy radiated by the transceiver LC antenna. Physically, a magnetic coupling occurs between the transceiver, also referred to as "reader", and transponder antennas To amplitude modulate (AM) the RF carrier, the transponder damps the electromagnetic field by switching a resistor in parallel with its coil. This way the transponder repetitively transmits its 128bit-identification code (ID) to the transceiver, which recovers the envelope of the damped field, and decodes the ID. The transceiver can send commands and data to the transponder by modulating the amplitude of the carrier. If the external RF field is AM modulated according to the asynchronous control pattern (ACP), the transponder stops transmitting the ID and enters the Program Mode. Data is then sent to the transponder using Return to One encoding. First half bit is low (0) or high (1), and the second half is high. In the middle of each half bit one sample is taken. In order for the transponder to detect the ACP modulation a minimum modulation depth is required. See timing specification below for more details on the write protocol. POR level The modulator consists of a modulation resistor that is switched in parallel with the resonant LC circuit (antenna). Because in weak RF fields the rising edge is much slower than the falling edge of the envelope, a symmetrically driven modulator would give an asymmetrical envelope. This is anticipated by delaying each falling edge by a fixed number of RF clock pulses. The modulator is hence driven asymmetrical. Each ON state is reduced by 8 (4) clocks in 2 (4) kBaud mode, and each OFF state is prolonged by the same amount. When the transponder is placed in an external radio frequency (RF) field of appropriate frequency and amplitude, the internal power supply (VDD) can build up as charge on the integrated buffer capacitance. The modulation resistor is switched on and off as soon as VDD has reached the Power On Reset (POR) level. When the modulation resistor is switched on, the LC circuit is no longer tuned, therefore no energy is taken from the field, and VDD drops due to internal consumption. Hence, by switching the modulation resistor on and off, it is possible to oscillate around the POR level. This phenomenon is referred to as hiccuping. The modulation resistor is switched off when the transponder drops below the POR level. Sensitivity level The minimum electromagnetic force (e.m.f.) needed to avoid hiccuping is defined by Vacsens. At this level the power supply will not drop below the POR level while the modulation resistance is switched on during modulation. RF limiter, or clamping The build up of voltage on the resonant LC circuit is limited to avoid damaging the internal circuit. Modulator Speed Total clocks per Bit Clocks ‘ON’ state Clocks ‘OFF’ state 2kbaud Long ON = 64 - 8 Long ON = 64 + 8 Short ON = 32 - 8 Short ON = 32 + 8 Long ON = 32 – 4 Long ON = 32 + 4 Short ON = 16 – 4 Short ON = 16 + 4 4kbaud 64 32 Clock recovery The transponder takes its clock from the carrier frequency. Depending on the speed option, the carrier frequency is divided by 32(4kbaud), 64(2kbaud) to generate the bit rate. MLX90111 128bit Read Write Transponder Page 5 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Following table shows the configuration of the tune caps in relation to the tune bits: EEPROM 1. Memory organization The EEPROM memory is arranged as 11 words of 16 bits each (see memory map above). Each one of these words is individually programmable. Tune bit Nominal capacitor value (pf) T4 64 T3 32 T2 16 T1 8 T0 4 1.1 ID (Addresses #0 to #7) The first 8 words hold the 128bits identification code (ID). Any of the 8 words of the ID can be individually written. The complete 128bits ID is send out when the device is in continuous/critical read mode. 1.2 Write Protect Word (Address #8) The 9th word allows writing protect some words from the ID temporarily or permanently, or even block the complete ID: OTP feature. Bits 0 to 7 (WPW flags) lock (1) or unlock (0) the write access to the corresponding word in the ID. The most significant byte (Lock WPW) is ignored, except when written with a special pattern (01010101 -MSB to LSB-). Then it locks the WPW (#8), the Tuning bits (#9) and the Configuration word (#10). When writing FF55Hex to the WPW word, then the transponder becomes an OTP device. 1.3 Tuning bits (Address #9) The tune bits select the status of the tuning capacitors (1=on, 0=off). They can be written with command CMF2 at address 9 in the bit positions 14 to 10 (from the highest, 64 pF to the lowest, 4 pF). The tune bits can be read back at address 12 with command CMF1. As the tune bits do not overlap with the configuration bits they can be read together in word 12. Programming is kept separate, to avoid reprogramming of the tune bits in case the code/speed is changed. The Tune capacitance can be delivered tuned to an absolute value of 250pF +/-2%, leaving 5% tuning after assembly, or tuned for maximum tuning range after assembly. The latter solution can only be provided with an absolute value ranging between 200 and 300pF, but over full lot tuned to 2%. This offer is only valid for large volume orders (>100k pieces). MLX90111 128bit Read Write Transponder 1.4 Configuration Word (Address #10) Speed bit (bit 0) defines the internal clock extraction: set to 1 for divided by 32, set to 0 for divided by 64. SPEED Data rate Baud rate 0 Freq/64 2kbaud 1 Freq/32 4kbaud Code bit (bit 1) defines if the ID will be encoded in Manchester (set to 1) or Biphase (set to 0) amplitude modulation scheme. Page 6 of 12 CODE Encoding 0 Biphase 1 Manchester Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder 2. Operating Modes 2.3 Programming commands Two Command Fields are defined: 2.1 Continuous/critical read mode (ID) In read mode, the transponder transmits its ID code to a transceiver by amplitude modulating (AM) the envelope of the carrier coming from the transceiver. The 128 bits of the ID are Manchester or Biphase encoded. After POR the device will enter 'normal' read mode. The ID will be read out under optimal conditions. After programming any word of the ID, the device will automatically enter 'critical' read mode. The data is read at the 2 extremes of the reading window. When both readings are identical, the data retention is guaranteed as specified (Tret, Ncyc). If the two critical readings show a difference, the device is at its minimum coupling with the transceiver and it should be reprogrammed using a stronger field. Critical read mode can only be reset by removing the transponder from the RF field. 2.2 Programming mode Upon receiving an Asynchronous Control Pattern (ACP), the device enters program mode and waits during a Watchdog Delay period (TWD), for the start bit of the programming sequence. The programming sequence consists of a start bit, and a 32 bit command. The command starts with a 3bit Command Field (CMF), a 4bit address, an odd parity bit calculated over the address, a 16bit data word and an 8bit CRC calculated over the full command. If the programming sequence is received, the write access, parity and CRC are verified and command is executed if possible, else the transponders goes back into normal read mode. In case the command has been executed, the transponder waits again for a Watchdog Delay period TWD for a new programming command. In case of a timeout the device starts sending the ID code in critical read mode, until removal from the RF field. CMF Code CMF1 001 Action - Write ID words: addresses 0…7, - Read address 8,9,10 CMF2 000 - Write address 8,9,10 To write data, the respective CMF and address are sent out. If the write access, parity and CRC are verified, the data are written in the EEPROM at the specified location. For 2kbaud devices EEPROM programming takes 20ms, for 4kbaud devices programming is done in 10ms. To read the data in addresses 8, 9 and 10 CMF1 is used. - address 11 for reading the configuration word. - address 12 for reading the tuning (bit positions 14 to 10) and the configuration (bit positions 0 to 1) bits, see the memory map. If the parity and CRC are verified, the data is sent out during the time window normally allocated for the EEPROM programming. Data is sent with a start bit of ½ bit (!) time first, followed by twice the 16-bit data word, with critical read levels. The startbit allows to detect a leading 0 in Manchester coding, and allows the microcontroller to synchronize. Remark that this startbit is different from the start bit sent by the reader, which is a full bit. HINT: In case the reader requires more time to switch from write to read mode, the dummy data should be chosen such that the last CRC bits are 1, i.e. in Return to Zero code: no modulation needed on the reader antenna. This way the time for switching the reader can be extended. 2.3 Parity, CRC PAR is an odd Parity bit is calculated over the 4bit address The 8-bit CRC with polynomial u8+ u4+ u3+ u2+ u0 is calculated over the complete command string [CMF-ADDRESS-PAR-DATA]. Minimum field strength for reliable programming is set by the minimum induced e.m.f. Vacee on the transponder coil. u2 7 6 u3 5 LSB u4 4 u8 3 2 1 0 MSB Exclusive OR x MLX90111 128bit Read Write Transponder Page 7 of 12 Register Stage Data Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder 3 Timing specification 3.3 Transponder action 3.1 Asynchronous Control Pattern The Asynchronous Control Pattern (ACP) is sent by the reader to render the transponder silent (stop transmitting), and listen for a programming sequence. Before starting the ACP, the field must be stable at FHIGH for at least 5 bit periods (Tsetup). This guarantees that the reference level FTHRESHOLD is adjusted. The control pattern itself contains 4 transitions between high field FHIGH and low field FLOW, each of which should be 2.5bitperiods apart. The threshold level FTHRESHOLD adjusts itself exponentially to the average FHIGH over the last 20 periods (TCLK). The optimum modulation depth forced by the reader depends on the application and stretches between: 90%> (FHIGH-FLOW) / (FHIGH+FLOW) > 20% The transponder samples the field 2 times per bit. A first time is after the first quarter, the second time after the third quarter. The sample values are only retained when the modulation resistor is off. The other samples are dropped. 3.2 Synchronous Command When the ACP has been detected, the transponder modulation will be turned off, within maximum 6 bit periods after the last rising edge of the ACP. The transponder will now synchronize on the first falling edge it sees. This edge is generated by a startbit (SB=0), which has to be sent within a Timeout Window TWD. If no SB is detected the transponder will return to its original read mode. The SB may used to optimize the synchronization between tag and reader. Tip: always try to put the sampling time of the transponder at the end of the first half bit. This minimizes the influence of an increased the transponder Q at larger distance. However, if the modulated signal on the transponder takes several periods to drop, the SB may be extended with this time. This will shift the sampling moment forward. After this synchronisation step, a synchronous command can be sent from the base station. Make sure to respect the nr of transponder clocks per bit, as specified below. All data sent by the reader have to be ReturnTo-One encoded. MLX90111 128bit Read Write Transponder The command is verified on its Parity and CRC values after the full command has been received. If verification is successful the command will be executed during the next 32 bit periods. Else if no valid command is received, due to a verification error, the transponder will immediately, i.e. 32 bit periods after the SB, start modulating its 128bit ID code. 3.3 Multiple commands After successfully receiving a command, the transponder will wait for a new command. This new timeout window (TWD) starts after the 32 bit period it requires to execute the received command. To limit time skew between microcontroller and the transponder, a new synchronization is done before each new command. The transponder will start modulating its ID code approximately 52 btiperiods after successfully having received its last command. 3.4 Other timings See timing table below for an overview of all timings. All timings are bitperiod based, and are therefore related to the resonance frequency and datarate. Page 8 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Data send to transponder as number of bit periods Asynchron Tsetup ACP TWD Synchron Bit periods >5 3*Tas + 6bit 20 TWD SB CMF ADDR PAR DATA CRC PROG/READ 1 3 4 1 16 8 32 SB 20 1 Transponder mode / operations Normal read Enter program mode: Read (32-bit) command - Stop modulation - Synchronize on Start bit Verify command + Write / Read EEPROM data Resynchronize on Start bit MLX90111 Timing Specifications in ms for a Carrier Freq = 125kHz, Tclk=8µ s Speed Bit Period Tas TWD PROG/READ Min (2 bit) Max (3 bit) 20 bit 32 bit Tclk*128 Tclk*192 Tclk*1280 Tclk*2048 Freq/64 (2kbaud) Tclk*64 = 0.512 1.024 1.536 10.24 16.384 Freq/32 (4kbaud) Tclk*32 = 0.256 0.55 0.7 5.12 8.192 1. Modulation on Reader Antenna Tsetup ACP pattern Twd FHIGH FLOW Tas Tas Tas 6bit 0 - 0 0 1- ... SB-CMF1- ... 2. Modulation on Tag Antenna FHIGH FTHRESHOLD FLOW Biphase: 1 1 1 0 0 1 1 1 0 1 1 - - - - 3. 1+2 Superposed on Tag Antenna - X: samples taken by transponder - Dark shaded: reader coil modulation ON - Light shaded: reader coil modulation OFF MLX90111 128bit Read Write Transponder Page 9 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Manchester Code Binary Data X 1 1 1 1 0 1 0 1 1 0 0 X 0 1 1 0 1 0 0 1 1 0 0 X 1 1 1 1 0 1 0 1 1 0 0 Memory Output Modulation Output Biphase Code Binary Data Memory Output Modulation Output Return to One Binary Data Binary form Modulation Output Coding schemes Manchester For a “1” bit, there is a transition from 0 to 1 in the middle of the bit period. Reciprocal, for a “0” logic bit there is a transition from 1 to 0 in the middle of the bit period. Biphase At the beginning of each bit, a transition will occur. A logic bit “1” will keep its state for the whole bit duration and a logic bit “0” will show a transition in the middle of the bit duration. Return to One This encoding is used to modulate the reader antenna to send the commands to the transponder. For a “0” bit, there is a transition to 0 in the beginning of the bit period. In the middle of the bit period the state returns to 1. For a “1” bit, the level remains high for the entire bit period. MLX90111 128bit Read Write Transponder Flow Chart. Upon entering the RF field, the transponder "sees" increasing amplitude of the voltage between COIL and GND pins. It passes through a POR sequence, and enters the normal read mode, transmitting the ID continuously. If the reader sends an asynchronous control pattern (ACP), the transponder enters program mode. It receives an address, parity, a 16-bit data word and a CRC. When a write command has been successfully received, the word is stored at the given address. When a word of the ID is written, the critical read flag will be set. This flag can only be reset by removing the transponder from the electromagnetic field. When a read command for addresses #B (WPW) or #C (tune-bits, speed and code) has successfully been received, the transponder immediately sends back the requested information, once critical high and once critical low. If no new programming pattern is received during the Watchdog Delay period (TWD), the transponder checks the critical read flag and enters the appropriate read mode. Page 10 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Flow Chart. Critical Read=1? POR No Yes Continuous Normal Read (Transmit ID) Continuous Critical Read (Transmit ID) ASYNC detected Addresses: 0..7: Write Id 8: Write WPW 9: Write Tune bits A: Write Code, Speed bits B: Read WPW C: Read Tune, code and Speed bits Y Stop modulating Y Watchdog expired? N N Parity/WPW/CRC check OK? Y Write to ID? address[0..7] Y Set Critical Read=1 Y Program word in EEPROM Y Read Critical (Once High, Once Low) N Write to address 8/9/A? N N Read address B or C? MLX90111 128bit Read Write Transponder Page 11 of 12 Rev 1.12 5-Feb-01 MLX90111 128bit Read Write Transponder Unique Features • • • • • SO8 Pinout Flexible configuration. Simple fast programming. Large programming range. State of the art reading distance. 20% tuning range of resonance frequency after assembly. Pin Name Function 1 COIL Coil connection 1 2 TEST Pin to set chip in test mode 3 TEST Pin to set chip in test mode Keeping at Vdd/2 will reset the chip Cross Reference This product can typically replace Marin EM4069, TEMIC e5550, Philips HITAG or any other RW transponder in the 120kHz range. It provides an easy configurable, high performant replacement. 4 VSS(*) Coil connection 2 / ground connection 5 VSS(*) Coil connection 2 / ground connection 6 TEST Pin to set chip in test mode 7 VDD External chip supply for test mode 8 VSS (*) Coil connection 2 / ground connection (*) All three VSS pins are connected together thanks to the use of a fused lead frame. Absolute Maximum Ratings -0.7 to 7V Maximum current forced between coil and ground pin (Icoilmax) + / - 30mA Operating Frequency (Freq) 60 to 150kHz Normal Operating Temperature (Toper) -40 to 85°C Maximum Storage Temperature in SO8 (Tstore) -55 to 125°C Electrostatic discharge (HBM) on coil pin (Vesdcoil) 500V Electrostatic discharge (HBM) on other pins (Vesd) 1500V COIL 1 TEST 2 TEST 3 VSS 4 MLX 90111 Maximum Power Supply (VDDmax) 8 VSS 7 VDD 6 TEST 5 VSS Chip dimensions These are good approximations; exact position info is available on request. ESD Precautions 2130 Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. 6 600 7 4 Disclaimer MLX90111 128bit Read Write Transponder 1630 600 1 Melexis reserves the right to periodically make modifications to product specifications. The information included herein is believed to be accurate and reliable. However, Melexis assumes no responsibility for its use, nor for any infringements of patents or other rights of third parties which may result from its use. 2 Page 12 of 12 3 Rev 1.12 5-Feb-01