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an important notice at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. production data. TMS3705 scbs881e ? january 2010 ? revised october 2018 TMS3705 transponder base station ic 1 device overview 1 1.1 features 1 ? base station ic for ti-rfid ? rf identification systems ? drives antenna ? sends modulated data to antenna ? detects and demodulates transponder response (fsk) ? short-circuit protection ? diagnosis ? sleep-mode supply current: 0.2 ma ? designed for automotive requirements ? 16-pin soic (d) package 1.2 applications ? car access ? immobilization ? building access ? livestock reader 1.3 description the TMS3705 transponder base station ic is used to drive the antenna of a ti-rfid transponder system, to send data modulated on the antenna signal, and to detect and demodulate the response of the transponder. the response of the transponder is a frequency shift keyed (fsk) signal. the high or low bits are coded in two different high-frequency signals (134.2 khz for low bits and 123 khz for high bits, nominal). the transponder induces these signals in the antenna coil according an internally stored code. the energy that the transponder needs to send out the data is stored in a charge capacitor in the transponder. the antenna field charges this capacitor in a preceding charge phase. the ic has an interface to an external microcontroller. there are two configurations for the clock supply to both the microcontroller and the base station ic: 1. the microcontroller and base station ic are supplied with a clock signal derived from only one resonator: the resonator is attached to the microcontroller. the base station ic is supplied with a clock signal driven by the digital clock output of the microcontroller. the clock frequency is either 4 mhz or 2 mhz, depending on the selected microcontroller type. 2. the microcontroller and the base station each have their own resonator. the base station ic has an on-chip pll that generates a clock frequency of 16 mhz for internal clock supply only. only TMS3705ddrq1 is recommended in combination with aes transponder products (for example, trpws21gtea or rf430f5xxx). TMS3705edrq1 is recommended for best performance in combination with dst40, dst80, mpt transponders (for example, tms37145teax, tms37126xx, tms37x128xx, tms37x136xx, tms37x158xx, ri-trp-dr2b-xx, ri-trp-brhp-xx) and cannot be used in combination with aes transponder products. (1) for the most current part, package, and ordering information for all available devices, see the package option addendum in section 9 , or see the ti website at www.ti.com . (2) the sizes shown here are approximations. for the package dimensions with tolerances, see the mechanical data in section 9 . device information (1) part number package body size (2) TMS3705edrq1 soic (16) 9.9 mm 3.91 mm TMS3705ddrq1 soic (16) 9.9 mm 3.91 mm ordernow productfolder support &community tools & software technical documents
2 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 device overview copyright ? 2010 ? 2018, texas instruments incorporated 1.4 functional block diagram figure 1-1 shows the functional block diagram. figure 1-1. functional block diagram vref rf amplifier 10k a_tst sfb sense vdda ant1 ant2 vssa vss vdd sciotxct d_tst f_sel osc2 osc1 vssb control logic with mode control register controlled frequency divider digital demodulator transponder resonance-frequency measurement sci encoder power-on reset pll predrivers full bridge bandpass limiter diagnosis copyright ? 2016, texas instruments incorporated
3 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 revision history copyright ? 2010 ? 2018, texas instruments incorporated table of contents 1 device overview ......................................... 1 1.1 features .............................................. 1 1.2 applications ........................................... 1 1.3 description ............................................ 1 1.4 functional block diagram ............................ 2 2 revision history ......................................... 3 3 device characteristics .................................. 4 3.1 related products ..................................... 4 4 terminal configuration and functions .............. 5 4.1 pin diagram .......................................... 5 4.2 signal descriptions ................................... 5 5 specifications ............................................ 6 5.1 absolute maximum ratings .......................... 6 5.2 esd ratings .......................................... 6 5.3 recommended operating conditions ................ 6 5.4 electrical characteristics ............................. 7 5.5 thermal resistance characteristics for d (soic) package .............................................. 8 5.6 switching characteristics ............................. 8 5.7 timing diagrams ..................................... 9 6 detailed description ................................... 11 6.1 power supply ....................................... 11 6.2 oscillator ............................................ 11 6.3 predrivers ........................................... 11 6.4 full bridge ........................................... 11 6.5 rf amplifier ......................................... 11 6.6 band-pass filter and limiter ........................ 12 6.7 diagnosis ............................................ 12 6.8 power-on reset ..................................... 12 6.9 frequency divider ................................... 12 6.10 digital demodulator ................................. 12 6.11 transponder resonance-frequency measurement 13 6.12 sci encoder ......................................... 13 6.13 control logic ........................................ 14 6.14 test pins ............................................ 16 7 applications, implementation, and layout ........ 17 7.1 application diagram ................................. 17 8 device and documentation support ............... 18 8.1 getting started and next steps ..................... 18 8.2 device nomenclature ............................... 18 8.3 tools and software ................................. 19 8.4 documentation support ............................. 19 8.5 community resources .............................. 20 8.6 trademarks .......................................... 20 8.7 electrostatic discharge caution ..................... 20 8.8 export control notice ............................... 20 8.9 glossary ............................................. 20 9 mechanical, packaging, and orderable information .............................................. 21 2 revision history note: page numbers for previous revisions may differ from page numbers in the current version. changes from october 19, 2016 to october 31, 2018 page ? updated the paragraph that begins " the base station ic has an on-chip pll... " in section 1.3 , description ........... 1 ? removed TMS3705a1drg4, TMS3705bdrg4, and TMS3705cdrq1 and added TMS3705edrq1 in the device information table ............................................................................................................. 1 ? replaced TMS3705a1drg4 with TMS3705edrq1 in note (f) on figure 6-1 , operational state diagram for the control logic ......................................................................................................................... 15 ? changed the note " setting not allowed for TMS3705ddrq1 " on table 6-1 , mode control register (7-bit register) 16
4 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 device characteristics copyright ? 2010 ? 2018, texas instruments incorporated 3 device characteristics table 3-1 lists the characteristics of the TMS3705. table 3-1. device characteristics characteristic TMS3705 data rate (maximum) 8 kbps frequency 134.2 khz required antenna inductance 100 to 1000 h supply voltage 4.5 to 5.5 vdc transmission principle hdx, fsk 3.1 related products for information about other devices in this family of products or related products, see the following links. products for wireless connectivity connect more ? industry ? s broadest wireless connectivity portfolio products for nfc / rfid texas instruments provides one of the industry ? s largest, most differentiated nfc product portfolios enabling lower power solutions to meet a broad range of rf connectivity needs. companion products for TMS3705 review products that are frequently purchased or used with this product. reference designs the ti designs reference design library is a robust reference design library that spans analog, embedded processor, and connectivity. created by ti experts to help you jump start your system design, all ti designs include schematic or block diagrams, boms, and design files to speed your time to market.
5 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 terminal configuration and functions copyright ? 2010 ? 2018, texas instruments incorporated 4 terminal configuration and functions 4.1 pin diagram figure 4-1 shows the pinout of the 16-pin d (soic) package. figure 4-1. 16-pin d package (top view) 4.2 signal descriptions table 4-1 describes the device signals. table 4-1. signal descriptions terminal type description no. name 1 sense analog input input of the rf amplifier 2 sfb analog output output of the rf amplifier 3 d_tst digital output test output for digital signals 4 a_tst analog output test output for analog signals 5 ant1 driver output antenna output 1 6 vssa supply input ground for the full bridge drivers 7 ant2 driver output antenna output 2 8 vdda supply input voltage supply for the full bridge drivers 9 vdd supply input voltage supply for nonpower blocks 10 osc2 analog output oscillator output 11 osc1 analog input oscillator input 12 vss/vssb supply input ground for nonpower blocks and pll 13 nc not connected 14 scio digital output data output to the microcontroller 15 f_sel digital input control input for frequency selection (default value is high) 16 txct digital input control input from the microcontroller (default value is high) 1 2 3 4 13 14 15 16 nc scio f_sel txct a_tst d_tst sfb sense 5 6 7 10 11 12 osc2 osc1 vss/vssb ant2 vssa ant1 8 9 vdd vdda nc C no connection
6 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 specifications copyright ? 2010 ? 2018, texas instruments incorporated (1) stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 5 specifications 5.1 absolute maximum ratings (1) over operating free-air temperature range (unless otherwise noted) min max unit v dd supply voltage range vdd, vss/vssb, vdda, vssa ? 0.3 7 v v osc voltage range osc1, osc2 ? 0.3 v dd + 0.3 v v inout voltage range scio, txct, f_sel, d_tst ? 0.3 v dd + 0.3 v i inout overload clamping current scio, txct, f_sel, d_tst ? 5 5 ma v ant output voltage ant1, ant2 ? 0.3 v dd + 0.3 v i ant output peak current ant1, ant2 ? 1.1 1.1 a v analog voltage range sense, sfb, a_tst ? 0.3 v dd + 0.3 v i sense sense input current sense, sfb, a_tst ? 5 5 ma i sfb input current in case of overvoltage sfb ? 5 5 ma t a operating ambient temperature ? 40 85 c t stg storage temperature ? 55 150 c p d total power dissipation at t a = 85 c 0.5 w 5.2 esd ratings value unit v esd esd protection (mil std 883) 2000 v 5.3 recommended operating conditions min nom max unit v dd supply voltage vdd, vss/vssb, vdda, vssa 4.5 5 5.5 v f osc oscillator frequency osc1, osc2 4 mhz v ih high-level input voltage f_sel, txct, osc1 0.7 v dd v v il low-level input voltage txct, osc1 0.3 v dd v f_sel 0.2 v dd i oh high-level output current scio, d_tst ? 1 ma i ol low-level output current scio, d_tst 1 ma
7 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 specifications copyright ? 2010 ? 2018, texas instruments incorporated (1) specified by design (2) specified by design; functional test done for input voltage of 90 mv pp . (3) band-pass filter tested at three different frequencies: f mid = 134 khz and gain > 30 db; f low = 24 khz; f high = 500 khz. attenuation < ? 3 db (reference = measured gain at f mid = 134 khz). (4) internal resistance switched on and much lower than external sense resistance. 5.4 electrical characteristics v dd = 4.5 v to 5.5 v, f osc = 4 mhz, f_sel = high, over operating free-air temperature range (unless otherwise noted) parameter test conditions min typ max unit power supply (vdd, vss/vssb, vdda, vssa) i dd supply current sum of supply currents in charge phase, without antenna load 8 20 ma i sleep supply current, sleep state sum of supply currents in sleep state, without i/o currents 0.015 0.2 ma oscillator (osc1, osc2) g osc transconductance f osc = 4 mhz, 0.5 v pp at osc1 0.5 2 5 ma/v c in input capacitance at osc1 (1) 10 pf c out output capacitance at osc2 (1) 10 pf logic inputs (txct, f_sel, osc1) r pullup pullup resistance txct 120 500 k ? f_sel 10 500 logic outputs (scio, d_tst) v oh high-level output voltage 0.8 v dd v v ol low-level output voltage 0.2 v dd v full-bridge outputs (ant1, ant2) r ds_on sum of drain-source resistances full-bridge n-channel and p-channel mosfets at driver current i ant = 50 ma 7 14 ? duty cycle p-channel mosfets of full bridge 38% 40% 42% t on1 /t on2 symmetry of pulse durations for the p ? channel mosfets of full bridge 96% 104.5% i oc threshold for overcurrent protection 220 1100 ma t oc switch-off time of overcurrent protection short to ground with 3 ? 0.25 10 s t doc delay for switching on the full bridge after an overcurrent 2 2.05 2.1 ms i leak leakage current 1 a analog module (sense, sfb, a_tst) i sense input current sense, in charge phase ? 2 2 ma v dcref / v dd dc reference voltage of rf amplifier, related to vdd 9.25% 10% 11% gbw gain-bandwidth product of rf amplifier at 500 khz with external components to achieve a voltage gain of minimum 4 ? mv pp and 5-mv pp input signal 2 mhz o phase shift of rf amplifier at 134 khz with external components to achieve a voltage gain of 5-mv pp and 20 ? mv pp input signal 16 v sfb peak-to-peak input voltage of band pass at which the limiter comparator should toggle (2) at 134 khz (corresponds to a minimal total gain of 1000) 5 mv f low lower cut-off frequency of band-pass filter (3) 24 60 100 khz f high higher cut-off frequency of band-pass filter (3) 160 270 500 khz v hys hysteresis of limiter a_tst pin used as input, d_tst pin as output, offset level determined by band-pass stage 25 50 135 mv diagnosis (sense) i diag current threshold for operating antenna (4) 80 240 a
8 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 specifications copyright ? 2010 ? 2018, texas instruments incorporated electrical characteristics (continued) v dd = 4.5 v to 5.5 v, f osc = 4 mhz, f_sel = high, over operating free-air temperature range (unless otherwise noted) parameter test conditions min typ max unit phase-locked loop (d_tst) f pll pll frequency 15.984 16 16.0166 mhz f/f pll jitter of the pll frequency 6% power-on reset (por) v por_r por threshold voltage, rising v dd rising with low slope 1.9 3.5 v v por_f por threshold voltage, falling v dd falling with low slope 1.3 2.6 v (1) the junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a jedec-standard, high-k board, as specified in jesd51-7, in an environment described in jesd51-2a. 5.5 thermal resistance characteristics for d (soic) package parameter value unit r ja thermal resistance, junction to ambient (1) 130 c/w 5.6 switching characteristics v dd = 4.5 v to 5.5 v, f osc = 4 mhz, f_sel = high, over operating free-air temperature range (unless otherwise noted) parameter test conditions min typ max unit t init min time for txct high to initialize a new transmission from start of the oscillator after power on or waking up until reaching the idle state (see figure 5-1 , figure 5-2 , figure 5-3 ) 2 2.05 2.2 ms t diag delay between leaving idle state and start of diagnosis byte at scio normal operation (see figure 5-1 , figure 5-2 , figure 5-3 ) 2 2.12 2.2 ms t r delay between end of charge or end of program and start of transponder data transmit on scio see figure 5-1 , figure 5-2 , figure 5-3 . 3 ms t off write pulse pause see figure 5-5 . 0.1 ms t dwrite signal delay on txct for controlling the full bridge write mode 73 79 85 s t mcr nrz bit duration for mode control register see figure 5-4 . 121 128 135 s t sci nrz bit duration on scio asynchronous mode (see figure 5-6 ) 63 64 65 s t dstop low signal delay on txct to stop synchronous mode 128 800 s t t_sync total txct time for reading data on scio synchronous mode (see figure 5-7 ) 900 s t sync txct period for shifting data on scio synchronous mode (see figure 5-7 ) 4 64 100 s t l_sync low phase on txct synchronous mode (see figure 5-7 ) 2 32 t sync ? 2 s t ready data ready for output after scio goes high synchronous mode (see figure 5-7 ) 1 127 s
9 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 specifications copyright ? 2010 ? 2018, texas instruments incorporated 5.7 timing diagrams note: mcw = mode control write (to write into the mode control register) figure 5-1. default mode (read only, no writing into mode control register) note: mcw = mode control write (to write into the mode control register) figure 5-2. read-only mode (writing into mode control register) note: mcw = mode control write (to write into the mode control register) figure 5-3. write/read mode (writing into mode control register) start byte diagnostic byte t init t r t ch txct t diag charge write response data bytes phase scio initialize transmission mcw program t prog start byte diagnostic byte t init t r t ch txct t diag charge response data bytes phase scio initialize transmission mcw start byte diagnostic byte t init t r t ch txct t diag charge response data bytes phase scio initialize transmission mcw
10 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 specifications copyright ? 2010 ? 2018, texas instruments incorporated figure 5-4. mode control write protocol (nrz coding) figure 5-5. transponder write protocol figure 5-6. transmission on scio in asynchronous mode (nrz coding) figure 5-7. transmission on scio in synchronous mode (nrz coding) (for diagnosis byte and data bytes) txct phase charge high bit low program t ch t offh t offl t bith t bitl t init txct t mcr phase initialize transmission low start bit bit1 bit3 bit4 bit2 t mcr test bit charge end transmission bit5 bit6 bit7 stop bit scio byte ready t sync lsb 1 2 3 4 5 6 msb txct t ready shift data mcu reads data t l_sync t sync t t_sync stop bit scio start bit t sci lsb 1 2 3 4 5 6 msb t sci
11 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated 6 detailed description 6.1 power supply the device is supplied with 5 v by an external voltage regulator through two supply pins, one for providing the driver current for the antenna and the analog part in front of the digital demodulator and one for supplying the other blocks. the power supply supplies a power-on reset that brings the control logic into idle state as soon as the supply voltage drops under a certain value. in sleep state, the sum of both supply currents is reduced to 0.2 ma. the base station device falls into sleep state 100 ms after txct has changed to high. when txct changes to low or is low, the base station ic immediately goes into and remains in normal operation. 6.2 oscillator the oscillator generates the clock of the base station ic of which all timing signals are derived. between its input and output a crystal or ceramic resonator is connected that oscillates at a typical frequency of 4 mhz. if a digital clock signal with a frequency of 4 mhz or 2 mhz is supplied to pin osc1, the signal can be used to generate the internal operation frequency of 16 mhz. the oscillator block contains a pll that generates the internal clock frequency of 16 mhz from the input clock signal. the pll multiplies the input clock frequency depending on the logic state of the input pin f_sel by a factor of 4 (f_sel is high) or by a factor of 8 (f_sel is low). in the sleep state, the oscillator is off. 6.3 predrivers the predrivers generate the signals for the four power transistors of the full bridge using the carrier frequency generated by the frequency divider. the gate signals of the p-channel power transistors (active low) have the same width ( 1 cycle of the 16 mhz clock), the delay between one p-channel mosfet being switched off and the other one being switched on is defined to be 12 cycles of the 16-mhz clock. in write mode the first activation of a gate signal after a bit pause is synchronized to the received transponder signal by a phase shift of 18 . 6.4 full bridge the full bridge drives the antenna current at the carrier frequency during the charge phase and the active time of the write phase. the minimal load resistance the full bridge sees between its outputs in normal operation at the resonance frequency of the antenna is 43.3 ? . when the full bridge is not active, the two driver outputs are switched to ground. both outputs of the full bridge are protected independently against short circuits to ground. in case of an occurring short circuit, the full bridge is switched off in less than 10 s to avoid a drop of the supply voltage. after a delay time of less than 10 ms the full bridge is switched on again to test if the short circuit is still there. an overcurrent due to a resistive short to ground that is higher than the maximum current in normal operation but lower than the current threshold for overcurrent protection does not need to be considered. 6.5 rf amplifier the rf amplifier is an operational amplifier with a fixed internal voltage reference and a voltage gain of 5 defined by external resistors. the rf amplifier has a high gain-bandwidth product of at least 2 mhz to show a phase shift of less than 16 for the desired signal and to give the possibility to use it as a low-pass filter by adapting additional external components. the input signal of the rf amplifier is dc coupled to the antenna. the amplitude of the output signal of the rf amplifier is higher than 5 mv peak-to-peak.
12 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated 6.6 band-pass filter and limiter the band-pass filter provides amplification and filtering without external components. the lower cut-off frequency is approximately a factor of 2 lower than the average signal frequency of 130 khz, the higher cut-off frequency is approximately a factor of 2 higher than 130 khz. the limiter converts the analog sine-wave signal to a digital signal. the limiter provides a hysteresis depending on the minimal amplitude of its input signal. the duty cycle of its digital output signal is between 40% and 60%. the band-pass filter and the limiter together have a high gain of at least 1000. 6.7 diagnosis the diagnosis is carried out during the charge phase to detect whether the full bridge and the antenna are working. when the full bridge drives the antenna, the voltage across the coil exceeds the supply voltage so that the voltage at the input of the rf amplifier is clamped by the esd-protection diodes. for diagnosis, the sense pin is loaded on-chip with a switchable resistor to ground so that the internal switchable resistor and the external sense resistor form a voltage divider, while the internal resistor is switched off in read mode. when the voltage drop across the internal resistor exceeds a certain value, the diagnosis block passes the frequency of its input signal to the digital demodulator. the frequency of the diagnosis signal is accepted if eight subsequent times can be detected, all with their counter state within the range of 112 to 125, during the diagnosis time (at most 0.1 ms). the output signal is used only during the charge phase, otherwise it is ignored. when the short-circuit protection switches off one of the full-bridge drivers, the diagnosis also indicates an improper operation of the antenna by sending the same diagnostic byte to the microcontroller as for the other failure mode. during diagnosis, the antenna drivers are active. in synchronous mode the antenna drivers remain active up to 1 ms after the diagnosis is performed, without any respect to the logic state of the signal at txct (thus enabling the microcontroller to clock out the diagnosis byte). 6.8 power-on reset the power-on reset generates an internal reset signal to allow the control logic to start up in the defined way. 6.9 frequency divider the frequency divider is a programmable divider that generates the carrier frequency for the full-bridge antenna drivers. the default value for the division factor is the value 119 needed to provide the nominal carrier frequency of 134.45 khz generated from 16 mhz. the resolution for programming the division factor is one divider step that corresponds to a frequency shift of approximately 1.1 khz. the different division factors needed to cover the range of frequencies for meeting the resonance frequency of the transponder are 114 to 124. 6.10 digital demodulator the input signal of the digital demodulator comes from the limiter and is frequency-coded according to the high- and low-bit sequence of the transmitted transponder code. the frequency of the input signal is measured by counting the oscillation clock for the time period of the input signal. as the high-bit and low- bit frequencies are specified with wide tolerances, the demodulator is designed to distinguish the high-bit and the low-bit frequency by the shift between the two frequencies and not by the absolute values. the threshold between the high-bit and the low-bit frequency is defined to be 6.5 khz lower than the measured low-bit frequency and has a hysteresis of 0.55 khz.
13 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated the demodulator is controlled by the control logic. after the charge phase (that is during read or write phase) it measures the time period of its input signal and waits for the transponder resonance-frequency measurement to determine the counter state for the threshold between high-bit and low-bit frequency. then the demodulator waits for the occurrence of the start bit. for that purpose, the results of the comparisons between the measured time periods and the threshold are shifted in a 12-bit shift register. the detection of the start bit comes into effect when the contents of the shift register matches a specific pattern, indicating 8 subsequent periods below the threshold immediately followed by 4 subsequent periods above the threshold. a 2-period digital filter is inserted in front of the 12-bit shift register to make a start bit detection possible in case of a nonmonotonous progression of the time periods during a transition from low- to high-bit frequency. the bit stream detected by the input stage of the digital demodulator passes a digital filter before being evaluated. after demodulation, the serial bit flow received from the transponder is buffered byte-wise before being sent to the microcontroller by sci encoding. 6.11 transponder resonance-frequency measurement during the prebit reception phase, the bits the transponder transmits show the low-bit frequency, which is the resonance frequency of the transponder. the time periods of the prebits are evaluated by the demodulator counter. based on the counter states, an algorithm is implemented that ensures a correct measurement of the resonance frequency of the transponder: 1. a time period of the low-bit frequency has a counter state between 112 and 125. 2. the measurement of the low-bit frequency (the average of eight subsequent counter states) is accepted during the write mode, when the eight time periods have counter states in the defined range. the measurement during write mode is started with the falling edge at txct using the fixed delay time at which end the full bridge is switched on again. 3. the counter state of the measured low-bit frequency results in the average counter state of an accepted measurement and can be used to update the register of the programmable frequency divider. 4. the measurement of the low-bit frequency (the average of eight subsequent counter states) is accepted during the read mode, when the eight time periods have counter states in the defined range. the start of the measurement during read mode is delayed to use a stable input signal for the measurement. 5. the threshold to distinguish between high-bit and low-bit frequency is calculated to be by a value of 5 or 7 (see hysteresis in threshold) higher than the counter state of the measured low-bit frequency. 6.12 sci encoder an sci encoder performs the data transmission to the microcontroller. as the transmission rate of the transponder is lower than the sci transmission rate, the serial bit flow received from the transponder is buffered after demodulation and before sci encoding. the sci encoder uses an 8-bit shift register to send the received data byte-wise (least significant bit first) to the microcontroller with a transmission rate of 15.625 kbaud ( 1.5 %), 1 start bit (high), 1 stop bit (low), and no parity bit (asynchronous mode indicated by the sync bit of the mode control register is permanently low). the data bits at the scio output are inverted with respect to the corresponding bits sent by the transponder. the transmission starts after the reception of the start bit. the start byte detection is initialized with the first rising edge. typical values for the start byte are 81_h or 01_h (at scio). the start byte is the first byte to be sent to the microcontroller. the transmission stops and the base station returns to the idle state when txct becomes low or 20 ms after the beginning of the read phase. txct remains low for at least 128 s to stop the read phase and less than 900 s to avoid starting the next transmission cycle.
14 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated the sci encoder also sends the diagnostic byte 2 ms after beginning of the charge phase. in case of a normal operation of the antenna, the diagnostic byte af_h is sent. if no antenna oscillation can be measured or if at least one of the full-bridge drivers is switched off due to a detected short circuit, the diagnostic byte ff_h is sent to indicate the failure mode. the sci encoder can be switched into a synchronous data transmission mode by setting the mode control register bit sync to high. in this mode, the output scio indicates by a high state that a new byte is ready to be transmitted. the microcontroller can receive the 8 bits at scio when sending the eight clock signals (falling edge means active) for the synchronous data transmission through pin txct to the sci encoder. 6.13 control logic the control logic is the core of the TMS3705 circuit. this circuit contains a sequencer or a state machine that controls the global operations of the base station (see figure 6-1 ). this block has a default mode configuration but can also be controlled by the microcontroller through the txct serial input pin to change the configuration and to control the programmable frequency divider. for that purpose a mode control register is implemented in this module that can be written by the microcontroller.
15 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated a. in sci synchronous mode, this transition always occurs approximately 3 ms after leaving idle state. diagnostic byte transmission is complete before the transition. b. a falling edge on txct interrupts the receive phase after a delay of 0.9 ms. txct must remain low for at least 128 s. if txct is still low after the 0.9-ms delay, the base station enters the idle state and then the diagnosis phase one clock cycle later (see the dotted line marked with " see note c " ). no mode control register can be written, and only the default mode is fully supported in this case. otherwise, if txct returns high and remains high during the delay, the base station stays in idle state and waits for txct to go low (which properly starts a new mode control register programming operation) or waits for 100 ms to enter the sleep state. c. this transition occurs only in a special case, as described in note b. d. a falling edge on txct interrupts the sleep state. only the default mode is fully supported when starting an operation from the sleep state with only one falling edge on txct, because of the 2-ms delay. for proper mode control register programming, txct must return to high and remain high during this delay. e. idle state is the next state in case of undefined states (fail-safe state machine). f. frequency measurement is available for the TMS3705edrq1 only. figure 6-1. operational state diagram for the control logic the default mode is a read-only mode that uses the default frequency as the carrier frequency for the full bridge. therefore the mode control register does not need to be written (it is filled with low states), and the communication sequence between microcontroller and base station starts with txct being low for a fixed time to initiate the charge phase. when txct becomes high again, the module enters the read phase and the data transmission through the scio pin to the microcontroller starts. there is another read-only mode that differs from the default mode only in the writing of the mode control register before the start of the charge phase. the method to fill the mode control register and the meaning of its contents is described in the following paragraphs. see note c power on sleep idle after approximately 2 ms approximately 2 ms after txct goes low (see note d) txct is low txct goes high before 96 s txct goes high mode control register programming write bits into mode control register diagnosis phase start of charge phase, perform diagnosis, send diagnostic byte approximately 2 ms after leaving idle state mode control register bits received charge phase charge phase continues diagnostic byte sent (see note a) write phase (see note f) start of write phase, frequency measurement, program phase receive phase frequency measurement, transponder signal demodulation, data output to mcu after reception of start byte txct remains high for 1.6 ms fail see note e after approximately 100 ms 0.9 ms after txct goes low (see note b) or approximately 4 ms after start of receive phase if no start bit is detected or otherwise approximately 20 ms after start of receive phase
16 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 detailed description copyright ? 2010 ? 2018, texas instruments incorporated (1) setting is not allowed for TMS3705ddrq1. the write-read mode starts with the programming of the mode control register. then the charge phase starts with txct being low for a fixed time. when txct becomes high again, the write phase begins in which the data are transmitted from the microcontroller to the transponder through the txct pin, the control logic, the predrivers, and the full bridge by amplitude modulation of 100% with a fixed delay time. after the write phase txct goes low again to start another charge or program phase. when txct becomes high again, the read phase begins. the contents of the mode control register (see table 6-1 ) define the mode and the way that the carrier frequency generated by the frequency divider is selected to meet the transponder resonance frequency as closely as possible. table 6-1. mode control register (7-bit register) bit reset value description name no. start_bit bit 0 0 start_bit = 0 the start bit is always low and does not need to be stored. data_bit1 bit 1 0 data_bit[4:1] = 0000 microcontroller selects division factor 119 data_bit[4:1] = 1111 division factor is adapted automatically (1) data_bit2 bit 2 0 data_bit[4:1] = 0001 microcontroller selects division factor 114 data_bit[4:1] = 0010 microcontroller selects division factor 115 data_bit3 bit 3 0 ... ... data_bit[4:1] = 0110 microcontroller selects division factor 119 data_bit4 bit 4 0 ... ... data_bit[4:1] = 1011 microcontroller selects division factor 124 sci_sync bit 5 0 sci_sync = 0 asynchronous data transmission to the microcontroller sci_sync = 1 synchronous data transmission to the microcontroller rx_afc bit 6 0 rx_afc = 0 demodulator threshold is adapted automatically rx_afc = 1 demodulator threshold is defined by data_bit[4:1] test_bit bit 7 0 test_bit = 0 no further test bytes test_bit = 1 further test byte follows for special test modes the TMS3705edrq1 can adjust the carrier frequency to the transponder resonance frequency automatically by giving the counter state of the transponder resonance-frequency measurement directly to the frequency divider by setting the first 4 bits in high state. the other combinations of the first 4 bits allow the microcontroller to select the default carrier frequency or to use another frequency. the division factor can be selected to be between 114 and 124. some bits are included for testability reasons. the default value of these test bits for normal operation is low. bit 7 (test_bit) is low for normal operation; otherwise, the base station may enter one of the test modes. the control logic also controls the demodulator, the sci encoder, the diagnosis, and the transmission of the diagnosis byte during the charge phase. the state diagram in figure 6-1 shows the general behavior of the state machine (the state blocks drawn can contain more than one state). all given times are measured from the moment when the state is entered if not specified otherwise. 6.14 test pins the ic has an analog test pin a_tst for the analog part of the receiver. the digital output pin d_tst is used for testing the internal logic. connecting both pins is not required.
17 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 applications, implementation, and layout copyright ? 2010 ? 2018, texas instruments incorporated 7 applications, implementation, and layout note information in the following applications section is not part of the ti component specification, and ti does not warrant its accuracy or completeness. ti's customers are responsible for determining suitability of components for their purposes. customers should validate and test their design implementation to confirm system functionality. 7.1 application diagram figure 7-1 shows a typical application diagram. figure 7-1. application diagram table 7-1 lists the bill of materials for the application in figure 7-1 . table 7-1. bill of materials (bom) component value comments r1 47 k r2 150 k l1 422 h at 134 khz sumida part number: vogt 581 05 042 40 c1 3 nf npo , cog (high q types). voltage rating must be 100 v or higher depending on q factor. c2 220 pf npo c3 220 pf npo c4 22 f low esr q1 4-mhz resonator murata part number: cstcr4m00g55b-r0. see resonator data sheet (load capacitance is important). TMS3705 sensesfb d_tst a_tst ant1 vssa ant2 vdda vdd osc2 osc1 vss nc scio f_sel txct 9 10 11 12 13 14 15 16 8 7 6 5 4 3 2 1 c3c2 q14 mhz c1 c4 txct input scio output 5 v ground antenna l1 r2 r1 copyright ? 2016, texas instruments incorporated
18 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 device and documentation support copyright ? 2010 ? 2018, texas instruments incorporated 8 device and documentation support 8.1 getting started and next steps rfid products from ti provide the ultimate solution for a wide range of applications. with its patented hdx technology, ti rfid offers unmatched performance in read range, read rate and robustness. for more information, see overview for nfc / rfid . 8.2 device nomenclature to designate the stages in the product development cycle, ti assigns prefixes to the part numbers of devices. each device has one of three prefixes: x, p, or null (no prefix) (for example, TMS3705 ). device development evolutionary flow: x experimental device that is not necessarily representative of the final device's electrical specifications and may not use production assembly flow. p prototype device that is not necessarily the final silicon die and may not necessarily meet final electrical specifications. null production version of the silicon die that is fully qualified. x and p devices are shipped against the following disclaimer: "developmental product is intended for internal evaluation purposes." production devices have been characterized fully, and the quality and reliability of the device have been demonstrated fully. ti's standard warranty applies. predictions show that prototype devices (x or p) have a greater failure rate than the standard production devices. ti recommends that these devices not be used in any production system because their expected end-use failure rate still is undefined. only qualified production devices are to be used. ti device nomenclature also includes a suffix with the device family name. this suffix indicates the package type (for example, d ). figure 8-1 provides a legend for reading the complete device name. for orderable part numbers of TMS3705 devices in the d package types, see the package option addendum in section 9 , the ti website , or contact your ti sales representative. figure 8-1. device nomenclature family TMS3705 = transponder base station ic revision a1, b, c, d = silicon revision packaging http://www.ti.com/packaging tape and reel r = large reel TMS3705 a family tape and reel revision packaging r d g4 qualification qualification g4 = green (rohs and no sb, br)q1 = q100 qualified
19 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 device and documentation support copyright ? 2010 ? 2018, texas instruments incorporated 8.3 tools and software design kits and evaluation modules low-frequency demo reader the adr2 evaluation kit contains a low-frequency reader required to evaluate and operate the ti car access products. the kit comes with a reader base board, lf antenna, and a usb-rs232 adapter. together with the pc software available online, all functions of the reader can be controlled and all automotive transponders, remote keyless entry, and passive entry devices can be addressed. operation of transponder functions and also passive entry communication is supported by the same system without component changes. palfi, passive low-frequency evaluation kit tms37157 the palfi evaluation kit contains all components required to evaluate and operate the tms37157. the kit comes with an ez430 msp430f1612 usb development stick, and an msp430 target board including an msp430f2274 plus the tms37157 palfi. a battery board for active operation in addition to an rfid base station reader/writer provide the infrastructure for various evaluation setups. 8.4 documentation support the following documentation describes the transponder, related peripherals, and other technical collateral. receiving notification of document updates to receive notification of documentation updates ? including silicon errata ? go to the TMS3705 product folder . in the upper right corner, click the "alert me" button. this registers you to receive a weekly digest of product information that has changed (if any). for change details, check the revision history of any revised document. application reports resonant trimming sequence this application report presents an efficient and precise method on how to achieve the desired resonant frequency of configuring the trim array with only a few iterations and measuring the resonant frequency. TMS3705 range extender power solution using ucc27424-q1 this application report provides supplementary information about the ti 134.2-khz rfid base station ic TMS3705x in combination with an external driver ic. in particular, the document shows a low cost and easy-to-implement solution to improve the communication distance between the transaction processor (trp) and the reader unit. TMS3705 passive antenna solution the ti low-frequency transponder technology provides the possibility to use a simple passive antenna in combination with various antenna cable lengths. this solution significantly reduces system costs because the active part of the transceiver can be added to the already existing host system; for example, the body control module (bcm) of a vehicle. integrated tiris rf module TMS3705a introduction to low frequency reader a tiris setup consists of one or more transponders and a reader. the reader described in this application note normally contains the reader antenna, the rf module and the control module. more literature wireless connectivity tri-fold overview at ti, we are committed to delivering a broad portfolio of wireless connectivity solutions which consume the lowest power and are the easiest to use. with ti innovation supporting your designs, you can share, monitor and manage data wirelessly for applications in wearables, home and building automation, manufacturing, smart cities, healthcare and automotive. msp430 ? ultra-low-power mcus and ti-rfid devices the ti portfolio of msp430 microcontrollers and ti-rfid devices is an ideal fit for low-power, robust rfid reader and transponder solutions. together, msp430 and ti-rfid devices help rf designers achieve low power consumption, best-in-class read range and reliable performance at a competitive price.
20 TMS3705 scbs881e ? january 2010 ? revised october 2018 www.ti.com submit documentation feedback product folder links: TMS3705 device and documentation support copyright ? 2010 ? 2018, texas instruments incorporated 8.5 community resources the following links connect to ti community resources. linked contents are provided "as is" by the respective contributors. they do not constitute ti specifications and do not necessarily reflect ti's views; see ti's terms of use . ti e2e ? online community the ti engineer-to-engineer (e2e) community was created to foster collaboration among engineers. at e2e.ti.com , you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. ti embedded processors wiki established to help developers get started with embedded processors from texas instruments and to foster innovation and growth of general knowledge about the hardware and software surrounding these devices. 8.6 trademarks ti-rfid, msp430, e2e are trademarks of texas instruments. all other trademarks are the property of their respective owners. 8.7 electrostatic discharge caution this integrated circuit can be damaged by esd. texas instruments recommends that all integrated circuits be handled with appropriate precautions. failure to observe proper handling and installation procedures can cause damage. esd damage can range from subtle performance degradation to complete device failure. precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 8.8 export control notice recipient agrees to not knowingly export or re-export, directly or indirectly, any product or technical data (as defined by the u.s., eu, and other export administration regulations) including software, or any controlled product restricted by other applicable national regulations, received from disclosing party under nondisclosure obligations (if any), or any direct product of such technology, to any destination to which such export or re-export is restricted or prohibited by u.s. or other applicable laws, without obtaining prior authorization from u.s. department of commerce and other competent government authorities to the extent required by those laws. 8.9 glossary ti glossary this glossary lists and explains terms, acronyms, and definitions.
21 TMS3705 www.ti.com scbs881e ? january 2010 ? revised october 2018 submit documentation feedback product folder links: TMS3705 mechanical, packaging, and orderable information copyright ? 2010 ? 2018, texas instruments incorporated 9 mechanical, packaging, and orderable information the following pages include mechanical, packaging, and orderable information. this information is the most current data available for the designated devices. this data is subject to change without notice and revision of this document. for browser-based versions of this data sheet, refer to the left-hand navigation.
package option addendum www.ti.com 21-nov-2018 addendum-page 1 packaging information orderable device status (1) package type package drawing pins package qty eco plan (2) lead/ball finish (6) msl peak temp (3) op temp (c) device marking (4/5) samples TMS3705bdrg4 active soic d 16 tbd call ti call ti -40 to 85 TMS3705b TMS3705ddrq1 active soic d 16 2500 green (rohs & no sb/br) cu nipdau level-3-260c-168 hr -40 to 85 TMS3705dq1 TMS3705edrq1 active soic d 16 2500 green (rohs & no sb/br) cu nipdau level-3-260c-168 hr -40 to 85 TMS3705eq1 (1) the marketing status values are defined as follows: active: product device recommended for new designs. lifebuy: ti has announced that the device will be discontinued, and a lifetime-buy period is in effect. nrnd: not recommended for new designs. device is in production to support existing customers, but ti does not recommend using this part in a new design. preview: device has been announced but is not in production. samples may or may not be available. obsolete: ti has discontinued the production of the device. (2) rohs: ti defines "rohs" to mean semiconductor products that are compliant with the current eu rohs requirements for all 10 rohs substances, including the requirement that rohs substance do not exceed 0.1% by weight in homogeneous materials. where designed to be soldered at high temperatures, "rohs" products are suitable for use in specified lead-free processes. ti may reference these types of products as "pb-free". rohs exempt: ti defines "rohs exempt" to mean products that contain lead but are compliant with eu rohs pursuant to a specific eu rohs exemption. green: ti defines "green" to mean the content of chlorine (cl) and bromine (br) based flame retardants meet js709b low halogen requirements of <=1000ppm threshold. antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) msl, peak temp. - the moisture sensitivity level rating according to the jedec industry standard classifications, and peak solder temperature. (4) there may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) multiple device markings will be inside parentheses. only one device marking contained in parentheses and separated by a "~" will appear on a device. if a line is indented then it is a continuation of the previous line and the two combined represent the entire device marking for that device. (6) lead/ball finish - orderable devices may have multiple material finish options. finish options are separated by a vertical ruled line. lead/ball finish values may wrap to two lines if the finish value exceeds the maximum column width. important information and disclaimer: the information provided on this page represents ti's knowledge and belief as of the date that it is provided. ti bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. efforts are underway to better integrate information from third parties. ti has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ti and ti suppliers consider certain information to be proprietary, and thus cas numbers and other limited information may not be available for release.
package option addendum www.ti.com 21-nov-2018 addendum-page 2 in no event shall ti's liability arising out of such information exceed the total purchase price of the ti part(s) at issue in this document sold by ti to customer on an annual basis.
tape and reel information *all dimensions are nominal device package type package drawing pins spq reel diameter (mm) reel width w1 (mm) a0 (mm) b0 (mm) k0 (mm) p1 (mm) w (mm) pin1 quadrant TMS3705edrq1 soic d 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 q1 package materials information www.ti.com 22-nov-2018 pack materials-page 1
*all dimensions are nominal device package type package drawing pins spq length (mm) width (mm) height (mm) TMS3705edrq1 soic d 16 2500 367.0 367.0 38.0 package materials information www.ti.com 22-nov-2018 pack materials-page 2

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