revision c page 1 october 2000 RX3141 low power if receiver ic himark technology, inc. reserves the right to change the product described in this datasheet. all information con- tained in this datasheet is subject to change without prior notice. himark technology, inc. assumes no responsibility for the use of any circuits shown in this datasheet. description the RX3141 is a low power if receiver ic which is fully compatible with the toshiba ta31145 ic and is suitable for use as the second if downconverter in double-conversion paging systems. the RX3141 is well-suited for pocsag paging applications and incor- porates a 2-level fsk demodulator consisting of a quadrature fm demodulator, on-chip bit-rate filter, and 1-bit comparator. an on-chip 1 v regulator is provided for convenient biasing of off-chip circuitry. in addition, an rssi voltage output is included as a measure of the received signal strength. features ! extremely low power operation with power-down feature ! built-in crystal oscillator for mixer local oscillator ! mixer input frequency: 10 ? 50 mhz ! rssi function ! quadrature detector ! on-chip bit-rate filter ! audio output ! 1-bit comparator with open collector output ! 1 v regulator ! 1.1 v low battery alarm ! tssop-20 package (0.65 mm pitch) applications ! pager ! wireless mouse ! two-way car alarm system the wireless ic company
RX3141 the wireless ic company revision c page 2 october 2000 block diagram and pin assignment 1.0 v 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 rssi mix in vss reg out reg con alm fsk out cha rge lpf out bs lpf in osc in osc out mix out ifin vcc dec fsk ref low battery alarm 1-bit comparator charge/ discharge circuit ifamp quad detector mixer oscillator regulator af out quad rssi
RX3141 the wireless ic company revision c page 3 october 2000 package and pin assignment: 20l, tssop symbols dimensions in mm dimensions in inch min. nom. max. min. nom. max. a --- --- 1.20 --- --- 0.048 a1 0.05 --- 0.15 0.002 --- 0.006 a2 0.80 1.00 1.05 0.031 0.039 0.041 b 0.19 --- 0.30 0.007 --- 0.012 c 0.09 --- 0.20 0.004 --- 0.008 d 6.40 6.50 6.60 0.252 0.256 0.260 e --- 6.40 --- --- 0.252 --- e1 4.30 4.40 4.50 0.169 0.173 0.177 e --- 0.65 --- --- 0.026 --- l 0.45 0.60 0.75 0.018 0.024 0.030 y --- --- 0.10 --- --- 0.004 0 --- 8 0 --- 8 himark mixin vss regout vcc regcon dec quad alm fskout charge bs lpfout lpfin RX3141 date code oscin oscout mixout ifin fskref rssi afout
RX3141 the wireless ic company revision c page 4 october 2000 pin descriptions number name i/o description 1 oscin i oscillator input (base) 2 oscout o oscillator output (emitter) 3 mixout o mixer output (2 k ? output impedance) 4 vcc power nominal 1.4 v supply 5 ifin i if amplifier input (2 k ? input impedance) 6 dec i if amplifier de-coupling capacitor connection 7 fskref i 1-bit comparator reference input (requires external capacitor) 8 quad i quadrature fm demodulator input 9 afout o quadrature fm demodulator output 10 rssi o rssi voltage output 11 lpfin i lpf operational amplifier input 12 lpfout o lpf operational amplifier output 13 bs i two-state logic input to control receiver power up/down. (bs = high = normal operation; bs = low = stand-by mode) 14 charge i two-state logic input to control charge-discharge circuit. (charge = high = fast charge; charge = low = slow charge) 15 fskout o open collector nrz comparator output (requires pull-up resistor) 16 alm o open collector low battery alarm output (requires pull-up resistor) 17 regcon o 1.0 v regulator control output for connection to external pnp base 18 regout i 1.0 v regulator input for connection to external pnp collector 19 vss gnd ground 20 mixin i mixer input (5 k ? input impedance)
RX3141 the wireless ic company revision c page 5 october 2000 absolute maximum ratings v ss = 0 v recommended operating conditions v ss = 0 v parameter symbol rating unit supply voltage v cc v ss ? 0.3 to v ss + 3.5 v operating temperature range t opr ?30 to 85 c storage temperature range t stg ?55 to 150 c soldering temperature range t sld 255 c soldering time range t sld 10 s parameter symbol va l u e unit min. typ. max. supply voltage range v cc1 1.11.351.6 v mixin input frequency f mixin 50 mhz operating temperature t a ?10 25 60 c
RX3141 the wireless ic company revision c page 6 october 2000 electrical characteristics (v cc = 1.4 v, v ss = 0 v, t a = 25 c, bs = high unless otherwise noted) parameter symbol condition va l u e unit min. typ. max. quiescent current consumption i cc,total 1.2 1.7 ma standby current consumption i cc,standby v bs = 0 v 5 a mixer conversion gain g c measured after 455 khz ceramic filter 912.516db mixer input intermodulation intercept point iip3 ?10 dbm mixer input resistance r in,mix 5k ? mixer output resistance r out,mix 2k ? if amplifier input resistance r in,if 2k ? s/n ratio 1 sn1 ?53 dbm at mixin 63 db s/n ratio 2 sn2 ?53 dbm at ifin 63 db s/n ratio 3 sn3 ?91 dbm at ifin 25 db demodulation output level vod ?53 dbm at ifin 45 mvrms am rejection ratio amr ?53 dbm at ifin, am=30 % 50 db fsk output duty ratio dr 40 50 60 % low battery alarm threshold voltage v alm 1.05 1.1 1.15 v regulator output voltage v regout 430 ? load resistor 0.95 1.0 1.05 v rssi output voltage v rssi ?53 dbm at ifin 0.45 0.60 0.80 v rssi output resistance r rssi 82 k ? charging/discharging current i ch v fskref = 0 v, v lpfout = 0.18 v 35 70 110 a alm logic high output current i oh,alm 2 a alm logic low output voltage v ol,alm 0.4 v fskout logic high output current i oh,fsk- out 2 a fskout logic low output voltage v ol,fsk- out 0.4 v
RX3141 the wireless ic company revision c page 7 october 2000 functional description the RX3141 if receiver ic incorporates a mixer, crystal-based local oscillator, if ampli- fier, quadrature fm demodulator, bit-rate filter, and 1-bit comparator and is capable of demodulating 2-level fsk input signals. in addition, 1.0 v regulator and 1.1 v low bat- tery alarm functions are provided. power-down function the entire receiver ic may be powered up and down through the control of the bs input (pin 13). during power down operation, the quiescent current consumption of the ic drops to approximately 0 a. the high input impedance of the bs pin allows for direct interfacing with the cmos output of an off-chip microcontroller. rssi function a dc potential, which corresponds to the input signal level received at the ifin input (pin 5), is developed across an internal 82 k ? resistor. this potential is a measure of the received signal strength and is provided at the rssi output (pin 10). charge/discharge circuitry the function of the charge/discharge circuitry is for both fast and slow charging/discharg- ing of the capacitor used for storing the voltage reference level of the fskref pin. the charge input (pin 14) should be enabled (charge = high = fast charge) immediately after transition of the receiver ic from power-down to normal operation in order to reduce the charging/discharging time for coarse adjustment of the fskref voltage to the appro- priate dc level ( i.e. dc level of the lpfout pin) and consequently to minimize the errone- ous output of the 1-bit comparator. during actual data reception, the charge pin should be set to low (charge = low = slow charge) for fine adjustment of the fskref voltage. 1-bit comparator the integrated 1-bit comparator operates as a data slicer and ?squares up? the bit-rate fil- tered output from the quadrature demodulator. the decision threshold voltage level for the 1-bit comparator is stored on an external capacitor connected to the fskref pin. regulator the on-chip 1.0 v regulator requires a suitable off-chip pnp transistor to achieve regula- tion. the external pnp transistor should have an h fe > 200 for . low battery alarm the low battery alarm output, alm, is normally low, but rises to 1.1 v ( vcc) when the vcc voltage falls below approximately 1.1 v. v ce 0.1 v
RX3141 the wireless ic company revision c page 8 october 2000 typical performance characteristics 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 440 445 450 455 460 465 470 ifin (khz) ifin (khz) ifin (khz) ifin (khz) lpfin (v) lpfin (v) lpfin (v) lpfin (v) vcc=1.4 v t=300 k if=-53 dbm f mod =600 hz ? f=4 khz -20 -15 -10 -5 0 440 445 450 455 460 465 470 ifin (khz) ifin (khz) ifin (khz) ifin (khz) vod (db) vod (db) vod (db) vod (db) vcc=1.4 v t=300 k ifin=-53 dbm f mod =600 hz ? f=4 khz 0 db=158 mv pk-pk -80 -60 -40 -20 0 20 40 60 80 0 0.1 0.2 0.3 0.4 0.5 fskref (v) fskref (v) fskref (v) fskref (v) i(charge) ( i(charge) ( i(charge) ( i(charge) ( 0 0. 2 0. 4 0. 6 0. 8 1 1 . 2 1 . 4 - 1 1 0- 1 00 - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20 - 1 00 mi xi n (dbm) vcc=1.4 v t=300 k mixin=21.4 mhz
RX3141 the wireless ic company revision c page 9 october 2000 test circuit 51 ? 1 nf 100 k ? 430 ? 2.2 f 100 k ? v regout vod v alm v fskout 68 k ? 68 k ? 330 pf 560 pf 68 k ? 0.01 f 22 k ? 56 pf 39 pf 0.1 f 10 f 0.1 f 10 f 3.3 k ? 10 f g c vcc vcc vcc vcc murata cfvm455e 2sa1015gr v rssi 10 nf 1.0 v 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 rssi mix in vss reg out reg con alm fsk out cha rge lpf out bs lpf in osc in osc out mix out ifin vcc dec fsk ref low battery alarm 1-bit comparator charge/ discharge circuit ifamp quad detector mixer oscillator regulator af out quad rssi
RX3141 the wireless ic company revision c page 10 october 2000 application circuit test nc opr le data clk ld nc xin xout vdd2 db do vss fin vdd1 dc/dc converter cpu lcd driver lcd driver rom ram decoder lna 1st mixer 1st if amplifier frequency multiplier ( 2,3) 1st lo himark fs8107e mixin vss regout regcon alm fskout charge bs oscin oscout mixout vcc ifin dec fskref quad himark RX3141 afout rssi lpfout lpfin
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