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SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 1 wireless & sensing datasheet SX1243 - low cost low curre nt integrated transmitter 310 to 928mhz frequency agile the SX1243 is an ultra-low-cost, fully integrated fsk or ook transmitter suitable for operation between 310 and 450 mhz, 860 and 870 mhz, as well as 902 and 928 mhz. for applications where economy is paramount, the SX1243 may be used without the requirement for configuration via an mcu. however, in conjun ction with a microcontroller the communication link parameters may be re-configured. including, output power, modulation format and operating channel. the SX1243 offers integrated radio performance with cost efficiency and is suited for operation in north america fcc part 15.231, fcc part 15.247 fhss and digital modulation techniques, 15.249, and europe en 300 220. pb-free, halogen free, ro hs/weee compliant product. ? garage door openers ? low-cost consumer electronic applications ? remote keyless entry (rke) ? remote control / security systems ? +10 dbm or 0 dbm configurable output power ? bit rates up to 100 kbps ? ook and fsk modulation. ? 1.8 to 3.7 v supply range. ? low bom fully integrated tx ? fractional-n pll with 1.5 khz typical step ? frequency agility for fhss modulation ? fcc cfr part 15.247 digital modulation techniques general description ordering information part number temperature range package moq / multiple SX1243iultrt -40 c to +85 c dfn-ut8 3000 pieces applications key product features pa cp sigma /delta xtal gnd data nreset rfout ctrl vdd m/n pfd 8 7 6 5 1 2 3 4 1.8 to 3.7 v tx_ready
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 2 section page wireless & sensing datasheet table of contents 1. circuit description ............... ......................................................................................... ............................................................... 3 1.1. general description ...................................................................................................... ...................................................... 3 1.2. block diagram ............................................................................................................ ........................................................ 3 1.3. pin description, dfn8 encapsulation............. ......................................................................... ........................................... 4 2. electrical characteristics ................................................................................................. ............................................................ 5 2.1. esd notice ............................................................................................................... .......................................................... 5 2.2. absolute maximum ratings ... .............................................................................................. ............................................... 5 2.3. operating range .......................................................................................................... ...................................................... 5 2.4. electrical specifications................................................................................................ ........................................................... 6 3. digital specification .......... ............................................................................................ ............................................................... 8 4. application modes of the sx124 3 ............. .............. .............. .............. .............. .............. ......... ................................................... 9 4.1. transmitter modes........................................................................................................ ...................................................... 9 4.2. mode selection flowchart ................................................................................................. ............................................... 10 4.3. application mode: power & go ............................................................................................ ................................................. 11 4.4. application mode: advanced . .............. .............. .............. .............. .............. .............. .......... ............................................. 11 4.4.1. advanced mode: configurat ion........................................................................................... ...................................... 11 4.4.2. frequency hopping spread spec trum...................................................................................... ................................ 11 4.5. frequency band coverage ........ .............. .............. .............. .............. .............. ........... ......... ................................................. 12 4.6. power consumption ........................................................................................................ ................................................. 12 5. SX1243 configuration .............. .............. .............. .............. .............. ........... ............ .......... ........................................................ 13 5.1. twi access............................................................................................................... ........................................................ 13 5.2. application conf iguration parameters ... .............. .............. .............. .............. .............. ............ ................................... 15 5.3. frequency configuration para meters ....................................................................................... .................................. 15 5.4. test parameters .......................................................................................................... ..................................................... 16 5.5. status parameters .................................. ...................................................................... .................................................... 16 5.6. recovery command ........................................................................................................ ...................................................... 17 6. application information.................................................................................................... .......................................................... 18 6.1. crystal specification .................................................................................................... ..................................................... 18 6.2. evaluation module ........................................................................................................ .................................................... 18 6.3. nreset pin ............................................................................................................... ...................................................... 20 6.4. tx_ready pin............................................................................................................. .................................................... 20 6.5. low power optimization ..... .............................................................................................. ................................................ 20 6.5.1. 2 connections: ctrl, data .............................................................................................. ...................................... 20 6.5.2. 3 connections: ctrl, data, tx_ready ........... ......................................................................... ........................... 20 7. SX1243 packaging........ .............. .............. .............. .............. ........... ........... ............ ......... ......................................................... 21 7.1. package outline drawing .................................................................................................. ............................................... 21 7.2. thermal impedance........................................................................................................ .................................................. 21 7.3. land pattern ............................................................................................................. ........................................................ 22 7.4. tape & reel specification ........................ ........................................................................ ................................................ 22 8. revision history ........................................................................................................... ............................................................. 23
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 3 integrated transmitter ic wireless & sensing datasheet this product datasheet contains a detailed descrip tion of the SX1243 performance and functionality. 1. circuit description 1.1. general description the SX1243 is a fully-integrated multi-band, single chip transmitter ic capable of fsk and ook modulation of an input data stream. it contains a frequency synthesizer which is a fractional -n sigma-delta pll. for frequency modulation (fsk), the modulation is made inside the pll bandwidth. for amplitude modulation (ook), the modulation is performed by turning on and off the output pa. the frequency reference used by the pll is generated by a 22, 24 or 26 mh z crystal oscillator, depending on the frequency band of interest. the power amplifier (pa), connected to the rfout pin, can deliver 0 dbm or +10 dbm in a 50 load. each of these two output powers need a specific matching networ k when efficiency needs to be optimized. the circuit can be configured via a simplif ied twi interface, constitute d of pin ctrl and data. the pins of this interface are also used to transmit the modulating data to the chip. another key feature of the SX1243 is its low current co nsumption in transmit and sleep modes and its wide voltage operating range from 1.8 v to 3.7 v. this makes the SX1243 su itable for low-cost battery chemistries or energy harvesting applications. 1.2. block diagram the figure below shows the simplified block diagra m of the SX1243 die mounted in a dfn8 package. figure 1. SX1243 simplified block diagram and bom pa cp sigma /delta xtal gnd data nreset rfout ctrl vdd m/n pfd 8 7 6 5 1 2 3 4 1.8 to 3.7 v tx_ready
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 4 integrated transmitter ic wireless & sensing datasheet 1.3. pin description, dfn8 encapsulation table 1 description of the SX1243 dfn8 pinouts number name type function in ?power & go? modes function in ?advanced? mode 0 gnd i exposed pad, ground 1 nreset i reset (optional, can be left floating) 2 data i/o transmit data transmit or configuration data 3gnd i ground 4 xtal i/o reference crystal 5 vbat i power supply 1.8v to 3.7v 6 ctrl i config selection configuration data clock 7 tx_ready o transmitter ready flag (optional, can be left floating) 8 rfout o transmitter rf output
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 5 integrated transmitter ic wireless & sensing datasheet 2. electrical characteristics 2.1. esd notice the SX1243 is an electrostatic di scharge sensitive device. it satisfies class 2 of the jedec standard jesd22-a114-b (human body model) on all pins. 2.2. absolute maximum ratings stresses above the values listed below may cause permanent device failure. exposure to absolute maximum ratings for extended periods may af fect device reliability. table 2 absolute maximum ratings 2.3. operating range operating ranges define the limits for functional operation and t he parametric characteristics of the device as described in this section. functionality outs ide these limits is not implied. table 3 operating range symbol description min max unit vddmr supply voltage -0.5 3.9 v tmr temperature -55 115 c tjunc junction temperature -55 125 c tstor storage temperature -55 150 c symbol description min max unit vddop supply voltage 1.8 3.7 v top operational temperature range -40 85 c clop load capacitance on digital ports - 25 pf
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 6 integrated transmitter ic wireless & sensing datasheet 2.4. electrical specifications the table below gives the electrical specifications of the transmitter under the following conditions: supply voltage vbat = 3.3 v, temperature = 25 c, f xosc = 26 mhz, f rf = 915 mhz, 2-fsk modulation with fdev=+/-10 khz, bit rate = 10 kbit/s and output power = +10 dbm terminated in a matched 50 ohm impedance, unless otherwise specified. table 4 transmitter specifications symbol description conditions min typ max unit current consumption iddsl supply current in sleep mode - 125 na iddt_315 supply current in transmit mode at 315 mhz* rfop=+10dbm 50% ook rfop=+10dbm fsk rfop=0dbm fsk - - - 11 15 9 - - - ma ma ma iddt_915 supply current in transmit mode at 915 mhz* rfop=+10dbm fsk rfop=0dbm fsk - - 17.5 10.5 - - ma ma rf and baseband specifications fband accessible frequency bands see details in table 7. band 0, with fxosc=22 mhz 310 - 450 mhz band 0, with fxosc=24 mhz 312 - 450 mhz band 0, with fxosc=26 mhz 338 - 450 mhz band 1, with fxosc=26 mhz 860 902 - - 870 928 mhz mhz fda frequency deviation, fsk 10 - 200 khz brf bit rate, fsk permissible range 0.5 - 100 kbps bro bit rate, ook permissible range 0.5 - 10 kbps ook_b ook modulation depth - 45 - db rfop rf output power in 50 ohms in either frequency band high power setting low power setting* 7 -3 10 0 - - dbm dbm rfopfl rf output power flatness from 315 to 390 mhz, 50 ohms load - 2 - db drfopv variation in rf output power with supply voltage 2.5 v to 3.3 v 1.8 v to 3.7 v - - - - 3 7 db db phn transmitter phase noise at offset: 100 khz 350 khz 550 khz 1.15 mhz - - - - -84 -94 -96 -105 - - - - dbc/hz dbc/hz dbc/hz dbc/hz step_22 rf frequency step fxosc = 22 mhz, band 0 - 1.34277 - khz step_24 rf frequency step fxosc = 24 mhz, band 0 - 1.46484 - khz step_26 rf frequency step fxosc = 26 mhz, band 0 fxosc = 26 mhz, band 1 - - 1.58691 3.17383 - - khz khz
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 7 integrated transmitter ic wireless & sensing datasheet * with different matching networks ** the oscillator startup time, ts_osc, depends on the electrical characteristics of the crystal *** from the last ctrl fallin g edge of the frequ ency change instruction to transmi tter ready (pa ramp up finished) fxosc crystal oscillator frequency - - - 22 24 26 - - - mhz mhz mhz dfxosc frequency variation of the xosc no crystal contribution - - +/-25 ppm timing specifications ts_tr time from sleep to tx mode xtal dependant, with spec?d xtal - 650 2000 us ts_hop0 channel hop time in band 0 315 to 390 mhz - 250 500 us ts_hop1 channel hop time in band 1 maximum hop of 26 mhz*** - 200 400 us tofft timer from tx data activity to sleep programmable - - 2 20 - - ms ms ramp pa ramp up and down time - 20 - us t_start time before ctrl pin mode selection. time from power on to sampling of ctrl ** - 200 us + ts_osc -ms symbol description conditions min typ max unit
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 8 integrated transmitter ic wireless & sensing datasheet 3. digital specification the following table gives the operati ng specifications for the digital inputs and outputs of the SX1243. table 5 digital signals specification symbol description conditions min typ max unit v ih digital input level high 0.8 - - vbat v il digital input level low - - 0.2 vbat v oh digital output level high imax = 1 ma 0.9 - - vbat v ol digital output level low imax = -1 ma - - 0.1 vbat f ctrl ctrl clock frequency - - 10 mhz t ch ctrl clock high time 45 - - ns t cl ctrl clock low time 45 - - ns t rise ctrl clock rise time - - 5 ns t fall ctrl clock fall time - - 5 ns t setup data setup time from data transition to ctrl rising edge 45 - - ns t hold data hold time from ctrl rising edge to data transition 45 - - ns t 0 , t 2 time at ?1? on data during recovery command see figure 9 and figure 10 - - 5 us t 1 time at ?0? on data during recovery command see figure 10 5 - - us
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 9 integrated transmitter ic wireless & sensing datasheet 4. application modes of the SX1243 pins ctrl and data are used for both configuring the circui t and sending the data to be transmitted over the air. two different modes are associated to these pins, ? power&go ? and ? advanced ? modes. 4.1. transmitter modes automatic mode operation is described in figure 2. here we see that a rising edge on the data pin activates the transmitter start-up process. data must be held high for th e start-up time (ts_tr) of the SX1243. during this time the SX1243 undergoes an optimized, self-cal ibrating trajectory from sleep mode to transmit mode. once this time has elapsed, the SX1243 is ready to transmit. any logical signal subsequently applied to the data pin is then transmitted. figure 2. ?power & go? mode: transmitter timing operation the transition back to sleep mode is managed automatically. the SX1243 waits for tofft (2 or 20 ms) of inactivity on data before returning to sleep mode. in forced transmit mode the circuit can be fo rced to wake up an d go to tx mode by sending an application instruction through the twi interface, and setting th e mode bit da(15) to ?1?. once in tr ansmit the circuit will transmit over the air the data stream pres ented on the data pin. the circuit will stay in transmit mode until a new application instruction is sent with da(15) to ?0?. figure 3. forced transmit mode description
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 10 integrated transmitter ic wireless & sensing datasheet 4.2. mode selection flowchart figure 4. SX1243 mode selection note advanced mode is entered only if data is held low during ctrl?s rising edge. when powering up the circuit (microcontrolle r and SX1243), the logic level of the ctrl pin is sampled after t_start, as described on figure 5. during t_start, the microcontroller io driving the ctrl pin must be configured as an output, driving the ctrl pin to the desired state. figure 5. power-up timing circuit start-up wait t_start power & go 1 868.3 mhz fsk, fdev=+/-19.2khz +10dbm check ctrl pin power & go 2 433.92 mhz ook +10dbm logic ?0? logic ?1? advanced mode full register flexibility automatic or forced transmit ctrl clock signal
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 11 integrated transmitter ic wireless & sensing datasheet 4.3. application mode: power & go the default ?power & go? application mode sees the SX1243 configured as detailed in table 6. by changing the logical state of the ctrl pin at power-up or reset, tw o distinct configuration modes can be selected. the power & go application modes hence permit microcontroller-less operation. table 6 configuration in power & go mode 4.4. application mode: advanced 4.4.1. advanced mode: configuration as described on figure 4, advanced mode is entered when ac cessing the two wire interface (twi) bus of the SX1243. upon communication to the register at up to 10 mhz of clocking speed, complete flexibility on the use of the chip is obtained. once all register settings are selected (see registers detailed description in section [5]), the SX1243 can be used either in automatic mode by simply toggling the data pin, or in forced transmit mode to optimize timings for instance. 4.4.2. frequency hopping spread spectrum frequency hopping is supported in advanced mode. after sending the data stream in the first channel, the user can send a frequency change instructio n containing the new channel frequency. the circuit will autom atically ramp down the pa, lock the pll to the new frequency, and turn the power amplifier back on. the user can then send his packet data on the new channel. timings are detailed hereafter: figure 6. frequency hopping description notes - during any twi access, the in put of the modula tor is inhibited - the time between two frequency change in structions shall be greater than ts_hopi - fhss modulation, as described under fcc part 15.247, is supported by the SX1243; also note that the large frequency deviation settings available on the SX1243 ma ke it suitable for ?digitally modulated systems?, as described under fcc part 15.247 (a)(2) ctrl pin configuration mode ?low? fsk 868.3 mhz, +10 dbm, fdev=+/-19.2 khz power&go 1 ?high? ook 433.92 mhz, +10 dbm power&go 2 tx channel b data t < tofft (2 or 20 ms) frequency change ctrl frequency change twi instruction rfout t < tofft (2 or 20 ms) ts_hop i tx channel a 5th falling edge on ctrl 24th falling edge on ctrl
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 12 integrated transmitter ic wireless & sensing datasheet 4.5. frequen cy band coverage the SX1243 offers several comb inations or frequency references and freque ncy outputs, allowing for maximum flexibility and design of multi-band products: table 7 frequency selection table 4.6. power consumption the following typical power consumption fi gures are observed on the SX1243 kits. note that the transmitter efficiency depends on the impedance matching quality, and can be pcb design dependant. the pa matching may be different in each frequency band. table 8 power consumption in tx mode reference frequency fxosc band setting da(13) upper / lower frequency bounds fstep frf & fdev 22 mhz 0 310 to 450 mhz 24 mhz 312 to 450 mhz 26 mhz 338 to 450 mhz 1 860 to 870 mhz and 902 to 928 mhz frequency band conditions typical current drain 310 to 450 mhz pout=+1 0dbm, ook modulation with 50% duty cycle pout=+10dbm, fsk modulation pout=0dbm, fsk modulation 11 ma 15 ma 9 ma 860 to 870 mhz pout=+10dbm, fsk modulation pout=0dbm, fsk modulation 16.5 ma 10 ma 902 to 928 mhz pout=+10dbm, fsk modulation pout=0dbm, fsk modulation 17.5 ma 10.5 ma fstep 22 x 10 6 2 14 ----------------- 1.34277 khz = = frf df 18 0 ; () fstep = fdev da 12 5 ; () fstep = fstep 24 x 10 6 2 14 ----------------- 1.46484 khz = = fstep 26 x 10 6 2 14 ----------------- 1.58691 khz = = fstep 26 x 10 6 2 13 ----------------- 3.17383 khz = =
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 13 integrated transmitter ic wireless & sensing datasheet 5. SX1243 configuration the SX1243 has several configuration parameters whic h can be selected through the serial interface 5.1. twi access as long as ctrl is kept stable, the data pin is considered by t he circuit as the input for the data to be transmitted over the air (power&go modes). programming of the configuration register is triggered by a risi ng edge on the ctrl line. upon detection of this rising edge, the data applied to the data pin is accepted as register conf iguration information, the data bits are clocked on subsequent rising edges of the clocking signal applied to the ctrl pin. th e timing for SX1243 configuration register ?write? is shown in figure 7. note that, once trig gered, all 24 clock cycle must be issued to the SX1243. figure 7. twi configuration register ?write?. the registers may, similarly, be read using the timing of figure 8. figure 8. twi configuration register ?read?. the first rising edge on ctrl which initiates the advanced mode must occur at least 1 ms after the circuit has been powered up or reset. data ctrl 1st 2nd 23rd 24th data pin is an input data pin is an output data pin is an input data ctrl 1st 2nd 8th 24th
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 14 integrated transmitter ic wireless & sensing datasheet table 9 twi instruction table notes - the first ?0? transmitted to the SX1243 is required to initialize communication - the following 3 bits (highlighted in bl ue) determine the type of instruction - the forthcoming bits (highlighted in green) define a protecti on pattern; any error in these bits voids the instruction byte 0 byte 1 byte 2 instruction 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 (0000) da(15:0) write application bits 0 0 0 1 1 df(18:0) write frequency bits 0 0 1 0 (0)(0010)(0010) dt(10:0) write test bits (pad protected) 0 0 1 1 (0011) da(15:0) read application bits 0 1 0 0 (0100) df(15:0) read the 16 least significant frequency bits 0 1 0 1 (0101) ds(12:5) ds(4:0) df(18: 16) read chip version, status and 3 most significant frequency bits 0 1 1 0 (0110) ds(28:13) read bist signature 0 1 1 1 (0111) (1111)(1) dt(10:0) read te s t b i ts 1 x discarded , not an instruction all 1 recovery instruction
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 15 integrated transmitter ic wireless & sensing datasheet 5.2. application c onfiguration parameters note all changes to the application para meters must be performed when the device is in sl eep mode, with the exception of da(15). mode can be sequentially written to ?1 ?, and then ?0? while the device is in transmit mode, to speed up the turn off process and circumvent the tofft delay. 5.3. frequency conf iguration parameters if done in sleep mode, the frequency cha nge instruction will be applied next time the SX1243 is turned on. if frequency change occurs during transmis sion, the automated fr equency hopping sequence described in section [4.4.2] will take place. name number description power &go 1 power &go 2 mode da(15) mode: 0 ? automatic mode 1 ? forced transmit mode 0 modul da(14) modulation scheme: 0 ? fsk 1 ? ook 01 band da(13) band 0, 310 to 450 mhz band 1, 860 to 870 mhz and 902 to 928 mhz 10 fdev da(12:5) rf frequency deviation in fsk mode only see table 7 for details 0x06 fdev= +/-19.2khz unused pout da(4) output power range: 0 ? 0 dbm 1 ? 10 dbm 11 tofft da(3) period of inactivity on data before SX1243 enters sleep mode in automatic mode: 0 ? 2 ms 1 ? 20 ms 01 res da(2:0) reserved 100 100 table 10 application configuration parameters name number description power &go 1 power &go 2 frf df(18:0) rf operating frequency see table 7 for details 0x42cad frf=868.3 mhz with 26 mhz reference 0x42c1c frf=433.92 mhz with 26 mhz reference table 11 frequency configuration parameters
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 16 integrated transmitter ic wireless & sensing datasheet 5.4. test parameters ten test bits dt(9:0) exist in the SX1243. they are only use fo r the industrial test of the devic e, and therefore they are pad protected. it means that their value cannot be modified without applying a specific logical level to some of the SX1243 pads during a write access. 5.5. status parameters ds(12:5) are read-only bits, organized as follows: name number description default advanced mode power &go 1 power &go 2 res ds(28:13) reserved - chip version ds(12:5) chip identification number ?0001 0001? --> v1a res ds(4:2) reserved - tx_ready ds(1) tx_ready, see section [6.5.1] 0 ? transmitter not ready 1 ? transmitter is ready - res ds(0) reserved - table 12 status read-only parameters
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 17 integrated transmitter ic wireless & sensing datasheet 5.6. recovery command in the event of spurious activity (less than 24 clock cycles re ceived) on the ctrl pin, contro l over the twi interface can be recovered in two possible ways: figure 9. quick recovery command figure 10. pulsed recovery command notes - if t2 < 5 us, the SX1243 will not tu rn into tx mode during the recovery co mmand (if not previously in tx mode) - if t1 < 5 us, with t0 > 5 us, the sx1 243 will not turn into tx mode in the second scenario of recovery command - during the pulsed recovery command, t0 timing does not have any upper limit - if t1 or t2 exceeds 5us, the recovery command will still be successful, but the transm itter will momentarily turn on data ctrl recovery command 24th rising edge on ctrl t2 1st rising edge on ctrl t0 t1 1st rising edge 24th rising edge data ctrl
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 18 integrated transmitter ic wireless & sensing datasheet 6. application information 6.1. crystal specification the SX1243 is designed to operate with a low-cost 22, 24 or 26 mhz crystal table 13 SX1243 quartz crystal reference oscillator specification 6.2. evaluation module figure 11. evaluation board schematic the evaluation module, presented in figure 11, allows for the seamless evaluation of the SX1243 circuit. several bom options are offered to evaluate the performance in all frequency bands. symbol description min typ max unit fxosc crystal frequency - 22 24 26 - mhz lm crystal motional inductance - 14.970 13.700 12.655 - mh cm crystal motional capacitance - 3.495 3.209 2.962 - ff rs crystal serial resistance - 20 100 ohms c0 crystal shunt capacitance - 1.0 7.0 pf cl load capacitance - 15 - pf
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 19 integrated transmitter ic wireless & sensing datasheet the SX1243 reference design uses a tiny footprint of 16 x 6 mm, allowing for compact implementations on 2-layer pc boards. figure 12. evaluation board layout top, bottom views the following boms guarantee that the SX1243 product will be able to meet all regional regulato ry requirements, with significant margin (more than 10db) on the rejection of harmonics and spurs. figure 13. evaluation board boms usage label 350 mhz 433 mhz 868 mhz 915 mhz @+10dbm 915 mhz @0dbm type tolerance l1 120nh 120nh 22nh 22nh 22nh l2 39nh 33nh 12nh 12nh 12nh l3 15nh 15nh 4.7nh 6.8nh 6.8nh l4 0 ohm 0 ohm 8.2nh 0 ohm 6.8nh c1 2.2pf 0.5pf - 0.5pf 0.5pf c2 100pf 100pf 33pf 18pf 18pf c3 8.2pf 8.2pf 1.8pf 5.6pf 5.6pf c4 3.3pf 2.2pf 1.5pf - - c5 8.2pf 8.2pf 1.8pf 2.2pf 2.2pf c6 - - 18pf - 18pf c7 --- - - c8 100pf 100pf 100pf 100pf 100pf npo c9 100nf 100nf 100nf 100nf 100nf x7r r5 --- - - - c10 --- - - - l5 c11 c12 334 3 4 777 6 7 110 1 0 pa matching and harmonic filtering lqg15xxx standard tolerance npo decoupling delayed por resistor count antenna match antenna dependant inductor count capacitor count
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 20 integrated transmitter ic wireless & sensing datasheet notes - the matching centered at 350 mhz offers a flat perfo rmance from 315 to 390 mhz, but could be modified to slightly improve efficiency at any frequency inbetween - the 915 mhz @10dbm bom is dedicated to systems runni ng under cfr part 15.247, either frequency hopping spread spectrum or digital modulation techniques operation - the 915 mhz @0dbm bom is dedicated to systems running under cfr part 15.249 6.3. nreset pin when required, the pin nr eset can be controlled ex ternally, to allow for: ? either a delayed power on reset (por) cycle of the SX1243, allowing for the companion micro to reset and assign its port directions. this is achi eved by connecting a r/c time constant to the nreset pin. ? or an on-the-go reset of the SX1243 at any moment in time, if required by the application. this is achieved by pulling the nreset pin low for more than 100 microseconds, then releasing it to hi gh impedance (nor mal termination). 6.4. tx_ready pin for timing critical applications, tx_read y pin can be useful to know precisely when the transmitter is ready for operation and therefore save energy. as an option tx_ready can be connected to inform the companion device that the pa ramp up phase has been terminated, hence the SX1243 is ready for data transmission. 6.5. low power optimization the SX1243 is designed to reduce the cost of the rf transmit ter functionnality. to this en d, a single data signal can be enough to operate the transmitter, in any of the two power & go modes. in this situati on, ts_start and tofft timings, tabulated in section 2.4, must be respected, leading to signifi cant periods of time during which the transmitter is on and no valuable information is transmitted. for more demanding applications where energy usage is cr itical, the SX1243 offers hardware and software support to accurately control the transmitter on time, and therefore save energy: 6.5.1. 2 connections: ctrl, data if the two signals of the twi interface can be controlled by t he host microcontroller, tx on time and energy usage can be optimized as follows: ? at the device turn on, instead of waiting for ts_tr (2ms max, but xtal dependant), th e status flag tx_ready can be polled on the twi interface. as soon as the tx_ready flag is set, the microcontroller can start toggling data to transmit the useful packet. this meth od is only valid in forced tx mode. ? at the device turn off, the user can imme diately turn off the transmitter after the transmission of packet, assuming that the forced transmit mode was used. 6.5.2. 3 connections: ctrl, data, tx_ready in applications where the number of connections between the microcontroller and the rf chip is less critical, tx_ready pin can be connected to either a gpio port, or an external in terrupt port of the micro. the two optimizations described in the former subsection will also be possible.
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 21 integrated transmitter ic wireless & sensing datasheet 7. SX1243 packaging 7.1. package outline drawing figure 14. package outline drawing 7.2. thermal impedance the thermal imped ance of this package, calculated from a package in still air, on a 4-layer fr4 pcb, as per the jedec standard, is theta ja = 67 c/w typ.
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 22 integrated transmitter ic wireless & sensing datasheet 7.3. land pattern figure 15. land pattern 7.4. tape & reel specification figure 16. tape & reel specification, dfn package
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 23 integrated transmitter ic wireless & sensing datasheet 8. revision history table 14 revision history revision date comment 1 january 2012 first final release 2 february 2012 add tape and reel specification add minimum order quantity add thermal impedance of the package add digital pins specifications typographical corrections modify sect ion [6.5.1] 3 may 2012 adjust electrical specifications
SX1243, rev 3, may 2012 ?2012 semtech corporation SX1243 www.semtech.com page 24 semtech corporat ion wireless & sensing products contact information e-mail: sales@semtech.com, acsupport@semtech. com internet: ht tp://www.semtech.com usa 200 flynn road, camarillo, ca 93012-8790. tel: +1 805 498 2111 fax: +1 805 498 3804 far east 12f, no. 89 sec. 5, nanking e. road, taipei, 105, twn, r.o.c. tel: +886 2 2748 3380 fax: +886 2 2748 3390 europe semtech ltd., units 2 & 3, park court, premier way, abbey park industrial estate, romsey, hampshire, so51 9dn. tel: +44 (0)1794 527 600 fax: +44 (0)1794 527 601 iso9001 certified wireless & sensing datasheet ? semtech 2012 a ll rights reserved. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. th e information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. no liability will be accepted by the publisher for any consequence of its use. publication thereof does not convey nor imply any license under patent or other industrial or intellectual property rights. semtech assumes no responsibility or liability whatsoever for any failure or unexpected operation resulting from misuse, neglect improper installation, repair or improper handling or unusual physical or electrical stress including, but not limited to, exposure to parameters beyond the specified maximum ratings or operation outside the specified range. semtech products are not designed, intended, authorized or warranted to be suitable for use in life-support applications, devices or systems or other critical applications. inclusion of semtech products in such applications is understood to be undertaken solely at the customer?s own risk. should a customer purchase or use semtech product s for any such unauthorized application, the customer shall indemnify and hold semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and attorney fees which could arise.

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