lt5504 1 5504f applicatio s u descriptio u features typical applicatio u rssi measurements receive agc transmit power control ask and envelope demodulation gsm/tdma/cdma/wcdma rf frequency range: 800mhz to 2.7ghz ultra wide dynamic range: 75db at 900mhz wide power supply range: 2.7v to 5.25v low supply current: 14.7ma at 3v 8-lead ms0p package 800mhz to 2.7ghz rf measuring receiver the lt 5504 is an 800mhz to 2700mhz monolithic inte- grated measuring receiver, capable of detecting a wide dynamic range rf signal from 75dbm to +5dbm. the logarithm of the rf signal is precisely converted into a linear dc voltage. the lt5504 consists of rf/if limiters, an lo buffer amplifier, a limiting mixer, a 3rd-order 450mhz integrated low pass filter, rf/if detectors and an output interface. the ultrawide dynamic range is achieved by simultaneously measuring the rf signal and a down- converted if signal obtained using the on-chip mixer and an external local oscillator. the rf- and if-detected sig- nals are summed to generate an accurate linear dc voltage proportional to the input rf voltage (or power) in db. the output is buffered with a low output impedance driver. , ltc and lt are registered trademarks of linear technology corporation. 5504 ta01a ? ? ? rf + rf v out r1 82 ? rf input enable gnd lo lo input output c3 10pf c1 100pf r2 200 ? en 3v v cc c2 1nf lt5504 rf detector if detector if detector output voltage and slope variation vs rf input power pin (dbm) ?0 v out (v) slope variation (db) 2.4 2.0 1.6 1.2 0.8 0.4 0 ?0 ?0 ?0 10 5504 ta01b ?0 50 ?0 ?0 0 6 4 2 0 ? ? ? f rf = 900mhz f if = 240mhz average slope:23mv/db
lt5504 2 5504f power supply voltage ............................................ 5.5v v out , en ................................................................ 0,v cc lo input power .................................................... 6dbm rf input power differential (50 ? , 5.5v) ............. 24dbm rf input power single-ended (50 ? , 5.5v) ......... 18dbm operating ambient temperature .............. 40 c to 85 c storage temperature range .................. 65 c to 150 c lead temperature (soldering, 10 sec).................. 300 c order part number t jmax = 150 c, ja = 160 c/w lt5504ems8 absolute axi u rati gs w ww u package/order i for atio uu w (note 1) electrical characteristics t a = 25 c. v cc = 3v, p lo = 10dbm, unless otherwise noted. (notes 2, 3) consult ltc marketing for parts specified with wider operating temperature ranges. 1 2 3 4 v cc rf + rf gnd 8 7 6 5 v cc v out lo en top view ms8 package 8-lead plastic msop ms8 part marking ltgp symbol parameter conditions min typ max units rf input f rf frequency range 800 to 2700 mhz input impedance (note 6) dc voltage internally biased 1.7 v lo input f lo frequency range 850 to 3100 mhz input return loss internally matched to 50 ? 14 db dc voltage internally biased 0.82 v p lo lo power 16 to 8 dbm lo to rf leakage 900mhz 50 dbc 1.9ghz 45 dbc 2.5ghz 40 dbc if frequency f if frequency 50 to 450 mhz output voltage at f rf = 900mhz, f lo = 1140mhz linear dynamic range (note 4) 66 75 db output voltage input = 70dbm 0.4 v input = 20dbm 1.6 v input = 0dbm 2.1 v average slope input from 50dbm to 20dbm 16 23 mv/db output voltage at f rf = 1900mhz, f lo = 2140mhz linear dynamic range (note 4) 60 72 db output voltage input = 70dbm 0.35 v input = 20dbm 1.52 v input = 0dbm 1.9 v average slope input from 50dbm to 20dbm 16 23 mv/db
lt5504 3 5504f note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. note 2: tests are performed as shown in the configuration of figure 5. note 3: specifications over the 40 c to 85 c temperature range are guaranteed by design, characterization and correlation with statistical process controls. electrical characteristics t a = 25 c. v cc = 3v, p lo = 10dbm, unless otherwise noted. (notes 2, 3) note 4: the linear dynamic range is defined as the range over which the output slope is at least 50% of the average slope from 50dbm to 20dbm. note 5: the output voltage is settled to the full specification within 1db. note 6: refer to figure 1 and applications information. note 7: refer to pin functions description. output voltage vs rf input power and frequency power up response time supply current vs supply voltage and temperature pin (dbm) 80 ?0 60 50 40 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g01 0 f rf = 900mhz f rf = 2.5ghz f if = 240mhz f rf = 1.9ghz supply voltage (v) 2.5 supply current (ma) 20 18 16 14 12 10 8 3.0 3.5 4.0 4.5 5504 g02 5.0 5.5 t a = 85 c t a = 25 c t a = 40 c 5504 g03 2 s/div v out 1v/div enable 1v/div v cc = 3v rf input power = 0dbm on off typical perfor a ce characteristics uw symbol parameter conditions min typ max units output voltage at f rf = 2500mhz, f lo = 2260mhz linear dynamic range (note 4) 58 70 db output voltage input = 70dbm 0.3 v input = 20dbm 1.45 v input = 0dbm 1.8 v average slope input from 50dbm to 20dbm 16 23 mv/db output interface current drive capability 400 a output noise spectral density at 100khz 3.9 v/ hz at 10mhz 0.32 v/ hz output response time (note 5) rf input pin from no signal to 0dbm 200 ns power up/down t on turn on time (note 5) 400 ns turn off time (note 5) 4 s input resistance 30 k ? enable turn on voltage (note 7) 0.6 ?v cc v disable turn off voltage (note 7) 0.4 ?v cc v power supply v cc supply voltage 2.7 5.25 v i cc supply current 14.7 22 ma shutdown current 30 a
lt5504 4 5504f pin (dbm) 80 ?0 ?0 ?0 ?0 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g09 0 f rf = 1.9ghz f if = 240mhz v cc = 5.25v v cc = 5.25v v cc = 2.7v v cc = 2.7v 6 4 2 0 ? ? ? slope variation (db) 5504 g12 100ns/div v out 1v/div pulsed rf 900mhz 0dbm 1v/div pin (dbm) 80 ?0 60 50 40 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g07 0 f rf = 1.9ghz average slope: 23mv/db t a = 40 c t a = 40 c 6 4 2 0 ? ? ? t a = 25 c slope variation (db) t a = 25 c t a = 85 c output voltage and slope variation vs rf input power and temperature, f if = 70mhz output voltage and slope variation vs rf input power and temperature, f rf = 900mhz output voltage and slope variation vs rf input power and if frequency output voltage and slope variation vs rf input power and temperature, f if = 400mhz output voltage and slope variation vs rf input power and supply voltage output voltage and slope variation vs rf input power and temperature, f if = 240mhz output response time pin (dbm) 80 ?0 60 50 40 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g05 0 f if = 240mhz average slope: 23mv/db t a = 85 c t a = 40 c t a = 40 c 6 4 2 0 ? ? ? slope variation (db) t a = 25 c t a = 25 c pin (dbm) 80 70 60 50 40 30 20 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g08 0 f rf = 1.9ghz average slope: 23mv/db 6 4 2 0 ? ? ? slope variation (db) 400mhz 240mhz 70mhz f if = 70mhz f if = 240mhz f if = 400mhz pin (dbm) 80 ?0 60 50 40 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g11 0 f rf = 1.9ghz average slope: 23mv/db t a = 40 c t a = 40 c 6 4 2 0 ? ? ? slope variation (db) t a = 25 c t a = 85 c t a = 25 c pin (dbm) 80 ?0 ?0 ?0 ?0 ?0 ?0 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g06 0 f if = 240mhz average slope: 23mv/db t a = 40 c t a = 40 c 6 4 2 0 ? ? ? t a = 25 c slope variation (db) t a = 25 c t a = 85 c output voltage and slope variation vs rf input power and temperature, f rf = 2.5ghz typical perfor a ce characteristics uw pin (dbm) 80 ?0 60 50 40 ?0 ?0 ?0 6 4 2 0 ? ? ? 10 5504 g04 0 f rf = 900mhz f rf = 2.5ghz f if = 240mhz average slope: 23mv/db 50% variation or slope = 11.5mv/db slope variation (db) f rf = 1.9ghz output slope variation vs rf input power and frequency pin (dbm) 80 70 60 50 40 30 20 ?0 v out (v) 2.4 2.0 1.6 1.2 0.8 0.4 0 10 5504 g10 0 f rf = 1.9ghz average slope: 23mv/db t a = 40 c t a = 40 c 6 4 2 0 ? ? ? slope variation (db) t a = 25 c t a = 25 c t a = 85 c (v cc = 3v unless otherwise noted).
lt5504 5 5504f uu u pi fu ctio s block diagra w v cc (pins 1, 8 ): power supply pins. these pins must be tied together at the part as close as possible, and should be decoupled using 1000pf capacitors. rf + (pin 2): positive rf input pin. rf (pin 3): negative rf input pin. gnd (pin 4): ground pin. en (pin 5): enable pin. the on/off threshold voltage is about v cc /2. when the input voltage is higher than 0.6 ?v cc , the circuit is completely turned on. when the input voltage is less than 0.4 ?v cc , the circuit is turned off. lo (pin 6): local oscillator input pin. v out (pin 7): output pin. 5504 bd 2 3 6 7 det det det det ? ? ? lo buffer rf limiter if limiter if limiter limiting mixer lpf rf + rf lo 5 en 4 gnd 1 8 v cc v cc v out + enable applicatio s i for atio wu uu the lt5504 consists of the following sections: rf/if limiters, limiting mixer, rf/if detectors, lo buffer ampli- fier, 3rd-order integrated low pass filter (lpf), output interface and bias circuitry. an rf signal ranging from 800mhz to 2.7ghz is detected by the rf and if detectors using a proprietary technique. the down-converted if signal is band limited by the on- chip lpf, reducing broadband noise, and thus an ultrawide dynamic range signal can be measured. the rf measuring receiver is essentially a logarithmic voltage detector. the measured output voltage is directly proportional to the rf signal voltage. an internal temperature compensation circuit results in a highly temperature-stable output volt- age. rf limiter the differential input impedance of the rf limiter is shown in figure 1. a 1:1 input transformer can be used to achieve 50 ? broadband matching with an 82 ? shunt resistor (r1) at the inputs as shown in figure 5. the 1:1 rf input transformer can also be replaced with a narrow band single-ended-to-differential conversion cir- cuit using three discrete elements as shown in figure 2. their nominal values are listed in table 1. due to the parasitics of the pcb, these values may require adjust- ment.
lt5504 6 5504f 1: 63.56 ? j98.05 ? 900.00mhz 2: 26.69 ? j42.90 ? 1.90ghz 3: 28.88 ? j27.76 ? 2.50ghz 1 2 3 start: 100mhz stop:3ghz 5504 f01 applicatio s i for atio wu u u limiting mixer and lpf the amplified rf signal is down-converted using the limiting mixer and lo signal. the resulting signal is filtered by the 3rd-order, 450mhz, integrated low pass filter (lpf). only the desired if signal is passed to the if limiters for further detection. any other mixing products, including lo feedthrough, are much reduced to maximize sensitivity. the receiver? sensitivity is thus defined by the lpf band- width. if limiter the if signal is then amplified through the multiple limiter stages for further signal detection. all dc offsets, includ- ing lo signal self-mixing, are eliminated by an internal dc offset cancellation circuit. nevertheless, care should be taken in component placement and in pcb layout to minimize lo coupling to the rf port. output interface the output interface of the lt55o4 is shown in figure 4. the output currents from the rf and if detectors are summed and converted into an output voltage, v out . the maximum charging current available to the output load is about 400 a. an internal compensation capacitor c c is used to guarantee stable operation for a large capacitive output load. the slew rate is 80v/ s and the small signal output bandwidth is approximately 5mhz when the output is resistively terminated. when the output is loaded with a large capacitor c l , the slew rate is limited figure 3 shows the output voltage vs rf input power response for these two input terminations. the voltage gain of the single-ended-to-differential conversion circuit is: gain log r db in == 20 50 3 ? where r in = 100 ? is the narrow band input impedance. thus, the output voltage curve in this case is shifted to the left by about 3db. table 1. the component values of matching network l sh , c s1 and c s2 f if (mhz) l sh (nh) c s1 /c s2 (pf) 900 12.0 3.9 1900 3.3 3.3 2500 2.7 2.2 2700 2.4 1.5 matching network rf input c s1 3.3pf c s2 3.3pf l sh 3.3nh to rf + to rf 5504 f02 2.5 2.0 1.5 1.0 0.5 0 pin (dbm) 80 ?0 ?0 ?0 ?0 ?0 ?0 ?0 v out (v) 10 5504 f03 0 f rf = 1.9ghz with single-ended-to- differential input circuit with 1:1 input tx figure 3. the output voltage vs rf input power figure 1. differential rf input impedance figure 2. rf input matching network at 1900mhz
lt5504 7 5504f v cc output currents from rf and if detectors v out c c 400 a 5504 f04 + typical applicatio s u to 400 a/c l . for example, the slew rate is reduced to 4v/ s when c l = 100pf. applicatio s i for atio wu u u figure 5. lt5504 evaluation board circuit schematic figure 6.component side silkscreen of evaluation board 5504 f04 1 2 3 4 8 7 6 5 v cc rf + rf gnd v cc v out lo en c2 100pf c3 1nf c7 100pf v out lo input v cc r1 82 ? r3 10k r2 200 ? r5 500k r4 20k c1 100pf c4 1nf rf input lt5504 jumper t1 toko 617db-1022 figure 4. simplified circuit schematic of the output interface information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. applications the lt5504 can be used as a self-standing signal strength- measuring receiver (rssi) for a wide range of input signals from 75dbm to +5dbm, for frequencies from 800mhz to 2.7ghz. the lt5504 can be used as a demodulator for am and ask modulated signals with data rates up to 5mhz. depending on specific application needs, the rssi output can be split into two branches, providing ac coupled data output, and dc coupled, rssi output for signal strength measure- ments and agc. refer to figure 5. the lt5504 can also be used as a wide range rf power detector for transmit power control. figure 9. bottom side layout of evaluation board figure 7. component side layout of evaluation board figure 8.bottom side silkscreen of evaluation board
lt5504 8 5504f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2002 lt/tp 0305 500 ? printed in usa related parts package descriptio u msop (ms8) 1001 0.53 0.015 (.021 .006) seating plane note: 1. dimensions in millimeter/(inch) 2. drawing not to scale 3. dimension does not include mold flash, protrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 0.152mm (.006") per side 4. dimension does not include interlead flash or protrusions. interlead flash or protrusions shall not exceed 0.152mm (.006") per side 5. lead coplanarity (bottom of leads after forming) shall be 0.102mm (.004") max 0.18 (.077) 0.254 (.010) 1.10 (.043) max 0.22 ?0.38 (.009 ?.015) 0.13 0.05 (.005 .002) 0.86 (.34) ref 0.65 (.0256) bcs 0 ?6 typ detail ? detail ? gauge plane 12 3 4 4.88 0.1 (.192 .004) 8 7 6 5 3.00 0.102 (.118 .004) (note 3) 3.00 0.102 (.118 .004) note 4 0.52 (.206) ref 5.23 (.206) min 3.2 ?3.45 (.126 ?.136) 0.889 0.127 (.035 .005) recommended solder pad layout 0.42 0.04 (.0165 .0015) typ 0.65 (.0256) bsc ms8 package 8-lead plastic msop (reference ltc dwg # 05-08-1660) part number description comments lt5500 receiver front end dual lna gain settling 13.5db/?4db at 2.5ghz, double balanced mixer, 1.8v v supply 5.25v lt5502 400mhz quadrature demodulator with rssi 1.8v to 5.25v supply, 70mhz to 400mhz if, 84db limiting gain, 90db rssi range lt5503 1.2ghz to 2.7ghz direct iq modulator and 1.8v to 5.25v supply, four-step rf power control, upconverting mixer 120mhz modulation bandwidth ltc5505 300mhz to 3.5ghz rf power detector >40db dynamic range, temperature compensated, 2.7v to 6v supply lt5506 500mhz quadrature if demodulator with vga 1.8v to 5.25v supply, 40mhz to 500mhz if, ?db to 57db linear power gain ltc5507 100khz to 1ghz rf power detector 48db dynamic range, temperature compensated, 2.7v to 6v supply ltc5508 300mhz to 7ghz rf power detector 44db dynamic range, temperature compensated, sc70 package ltc5509 300mhz to 3ghz rf power detector 36db dynamic range, sc70 package lt5511 high signal level upconverting mixer rf output to 3ghz, 17dbm iip3, integrated lo buffer lt5512 high signal level downconverting mixer dc-3ghz, 20dbm iip3, integrated lo buffer lt5515 1.5ghz to 2.5ghz direct conversion demodulator 20dbm iip3, integrated lo quadrature generator lt5516 0.8ghz to 1.5ghz direct conversion quadrature demodulator 21.5dbm iip3, integrated lo quadrature generator lt5522 600mhz to 2.7ghz high signal level mixer 25dbm iip3 at 900mhz, 21.5dbm iip3 at 1.9ghz, matched 50 ? rf and lo ports, integrated lo buffer ltc5532 300mhz to 7ghz precision rf power detector precision v out offset control, adjustable gain and offset voltage
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