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lt5516 1 5516f the lt ? 5516 is an 800mhz to 1.5ghz direct conversion quadrature demodulator optimized for high linearity re- ceiver applications. it is suitable for communications receivers where an rf or if signal is directly converted into i and q baseband signals with bandwidth up to 260mhz. the lt5516 incorporates balanced i and q mixers, lo buffer amplifiers and a precision, high frequency quadra- ture generator. in an rf receiver, the high linearity of the lt5516 provides excellent spur-free dynamic range, even with fixed gain front end amplification. this direct conversion receiver can eliminate the need for intermediate frequency (if) signal processing, as well as the corresponding require- ments for image filtering and if filtering. channel filtering can be performed directly at the outputs of the i and q channels. these outputs can interface directly to channel- select filters (lpfs) or to a baseband amplifier. n cellular/pcs/umts infrastructure n high linearity direct conversion i/q receiver n high linearity i/q demodulator , ltc and lt are registered trademarks of linear technology corporation. n frequency range: 800mhz to 1.5ghz n high iip3: 21.5dbm at 900mhz n high iip2: 52dbm n noise figure: 12.8db at 900mhz n conversion gain: 4.3db at 900mhz n i/q gain mismatch: 0.2db n shutdown mode n 16-lead qfn 4mm 4mm package with exposed pad 800mhz to 1.5ghz direct conversion quadrature demodulator figure 1. high signal-level i/q demodulator for wireless infrastructure bpf 5v v cc bpf rf + rf lpf lt5516 i out + i out 0 lo + lo input lo en enable lpf dsp q out + q out 90 0 /90 5516 f01 lna vga vga 20 0 ?0 ?0 ?0 ?0 100 rf input power (dbm) ?8 ?4 ?0 ? ? 26 5516 ta01 p out , im3 (dbm/tone) p out im3 v cc = 5v t a = 25 c p lo = ?0dbm f lo = 901mhz f rf1 = 899.9mhz f rf2 = 900.1mhz i/q output power, im3 vs rf input power applicatio s u features typical applicatio u descriptio u
lt5516 2 5516f power supply voltage ............................................ 5.5v enable voltage ...................................................... 0, v cc lo + to lo C differential voltage ............................... 2v (+10dbm equivalent) rf + to rf C differential voltage ................................ 2v (+10dbm equivalent) operating ambient temperature ..............C40 c to 85 c storage temperature range ................. C 65 c to 125 c maximum junction temperature .......................... 125 c order part number consult ltc marketing for parts specified with wider operating temperature ranges. lt5516euf absolute axi u rati gs w ww u package/order i for atio uu w (note 1) t a = 25 c. v cc = 5v, en = high, f rf1 = 899.9mhz, f rf2 = 900.1mhz, f lo = 901mhz, p lo = C10dbm unless otherwise noted. (notes 2, 3) (test circuit shown in figure 2) parameter conditions min typ max units frequency range 0.8 to 1.5 ghz lo power C13 to C 2 dbm conversion gain voltage gain, load impedance = 1k 2 4.3 db conversion gain variation vs temperature C 40 c to 85 c 0.01 db/ c noise figure r1 = 8.2 w 11.4 db r1 = 3.3 w , p lo = C5dbm 12.8 db input 3rd order intercept 2-tone, C10dbm/tone, r1 = 8.2 w 17.0 dbm d f = 200khz r1 = 3.3 w , p lo = C5dbm 21.5 dbm input 2nd order intercept input = C10dbm r1 = 8.2 w 46.0 dbm r1 = 3.3 w , p lo = C5dbm 52.0 dbm input 1db compression r1 = 8.2 w 6.6 dbm baseband bandwidth 260 mhz i/q gain mismatch (note 4) 0.2 0.7 db i/q phase mismatch (note 4) 1 degree output impedance differential 120 w lo to rf leakage C 65 dbm rf to lo isolation 57 db ac electrical characteristics 16 15 14 13 5 6 7 8 top view uf package 16-lead (4mm 4mm) plastic qfn 9 10 11 12 4 3 2 1 gnd rf + rf gnd v cc lo lo + v cc i out + i out q out + q out v cc v cm en v cc exposed pad is ground (must be soldered to pcb) t jmax = 125 c, q ja = 38 c/w uf part marking 5516
lt5516 3 5516f dc electrical characteristics t a = 25 c. v cc = 5v unless otherwise noted. parameter conditions min typ max units supply voltage 4 5.25 v supply current 80 117 150 ma shutdown current en = low 20 m a turn-on time 120 ns turn-off time 650 ns en = high (on) 1.6 v en = low (off) 1.3 v en input current v enable = 5v 2 m a output dc offset voltage f lo = 901mhz, p lo = C10dbm 1 25 mv ( ? i out + C i out C ? , ? q out + C q out C ? ) output dc offset variation vs temperature C 40 c to 85 c20 m v/ c 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 2 with r1 = 8.2 w , unless otherwise noted. note 3: specifications over the C 40 c to 85 c temperature range are assured by design, characterization and correlation with statistical process control. note 4: measured at p rf = C10dbm and output frequency = 1mhz.
lt5516 4 5516f typical perfor a ce characteristics uw i/q output power, im3 vs rf input power i/q gain mismatch vs rf input frequency supply current vs supply voltage conv gain, nf, iip3 vs rf input frequency iip2 vs rf input frequency supply voltage (v) 4 4.5 5 5.5 supply current (ma) 5516 g01 160 140 120 100 80 60 40 t a = 85 c r1 = 8.2 t a = 25 c t a = 40 c rf input frequency (mhz) 800 900 1000 1100 1200 1300 gain (db), nf (db), iip3 (dbm) 5516 g02 25 20 15 10 5 0 p lo = 10dbm t a = 25 c v cc = 5v r1 = 8.2 iip3 nf conv. gain rf input frequency (mhz) 800 900 1000 1100 1200 1300 iip2 (dbm) 5516 g03 70 60 50 40 30 20 p lo = 10dbm t a = 25 c v cc = 5v r1 = 8.2 rf input power (dbm) ?8 ?4 ?0 ? ? 26 p out , im3 (dbm/tone) 5516 g04 20 0 ?0 ?0 ?0 ?0 100 t a = 85 c t a = 40 c f lo = 901mhz v cc = 5v r1 = 8.2 output power im3 t a = 25 c rf input frequency (mhz) 800 900 1000 1100 1200 1300 1400 1500 gain mismatch (db) 5516 g05 1.2 0.8 0.4 0 0.4 0.8 1.2 p lo = ?0dbm f bb = 1mhz v cc = 5v r1 = 8.2 t a = 25 c t a = 40 c t a = 85 c (test circuit optimized for 900mhz operation as shown in figure 2)
lt5516 5 5516f typical perfor a ce characteristics uw rf input frequency (mhz) 800 900 1000 1100 1200 1300 1400 1500 phase mismatch (deg) 5516 g06 6 4 2 0 ? ? ? p lo = ?0dbm f bb = 1mhz v cc = 5v r1 = 8.2 t a = 40 c t a = 85 c t a = 25 c lo input power (dbm) ?4 ?2 ?0 ? ? ? ? nf (db) 5516 g07 18 16 14 12 10 8 6 4 f rf = 1300mhz f rf = 1100mhz f rf = 900mhz t a = 25 c v cc = 5v r1 = 8.2 lo input power (dbm) ?4 ?2 ?0 ? ? ? ? conv gain (db), iip3 (dbm) 5516 g08 20 16 12 8 4 0 f lo = 901mhz v cc = 5v r1 = 8.2 t a = 40 c t a = 85 c t a = 40 c t a = 85 c t a = 25 c t a = 25 c iip3 conv gain lo input power (dbm) ?4 ?2 ?0 ? ? ? ? iip2 (dbm) 5516 g09 70 65 60 55 50 45 40 35 30 f lo = 901mhz v cc = 5v r1 = 8.2 t a = 40 c t a = 85 c t a = 25 c supply voltage (v) 4 4.5 5 5.5 5516 g10 conv gain (db), iip3 (dbm) 20 16 12 8 4 0 f lo = 901mhz p lo = 10dbm r1 = 8.2 t a = 40 c t a = 85 c t a = 40 c t a = 85 c t a = 25 c iip3 conv gain t a = 25 c iip2 vs lo input power conv gain, iip3 vs supply voltage i/q phase mismatch vs rf input frequency nf vs lo input power conv gain, iip3 vs lo input power (test circuit optimized for 900mhz operation as shown in figure 2)
lt5516 6 5516f typical perfor a ce characteristics uw frequency (ghz) 0 0.5 1 1.5 2 2.5 return loss (db) 5516 g13 0 ? ?0 ?5 ?0 ?5 ?0 t a = 25 c v cc = 5v r1 = 8.2 rf lo 8 6 4 2 0 ? ? baseband frequency (mhz) 0.1 1 10 100 1000 5516 g14 conv gain (db) t a = 40 c t a = 85 c t a = 25 c f lo = 1000mhz v cc = 5v r1 = 8.2 lo input power (dbm) ?4 ?2 ?0 ? ? ? ? lo-rf leakage (dbm) 5516 g11 ?5 ?0 ?5 ?0 ?5 ?0 f rf = 900mhz f rf = 1300mhz f rf = 1100mhz t a = 25 c v cc = 5v r1 = 8.2 rf input power (dbm) ?5 10 ? 0 5 10 rf-lo isolation (db) 5516 g12 80 70 60 50 40 30 20 f rf = 900mhz f rf = 1300mhz f rf = 1100mhz t a = 25 c v cc = 5v r1 = 8.2 conv gain vs baseband frequency lo-rf leakage vs lo input power rf-lo isolation vs rf input power rf, lo port return loss vs frequency (test circuit optimized for 900mhz operation as shown in figure 2) conv gain, nf, iip3 vs r1 supply current, iip2 vs r1 r1 ( ) 3 0 gain (db), nf (db), iip3 (dbm) 5 10 15 20 25 4 567 5516 g15 89 t a = 25 c v cc = 5v p lo = ?dbm f lo = 901mhz iip3 nf conv gain r1 ( ) 3 30 supply current (ma), iip2 (dbm) 50 70 90 110 150 130 4 567 5516 g16 89 t a = 25 c v cc = 5v p lo = ?dbm f lo = 901mhz supply current iip2
lt5516 7 5516f gnd (pins 1, 4): ground pin. rf + , rf C (pins 2, 3): differential rf input pins. these pins are internally biased to 1.54v. they must be driven with a differential signal. an external matching network is required for impedance transformation. v cc (pins 5, 8, 9, 12): power supply pins. these pins should be decoupled using 1000pf and 0.1 m f capacitors. v cm (pin 6): common mode and dc return for the i-mixer and q-mixer. an external resistor must be connected between this pin and ground to set the dc bias current of the i/q demodulator. en (pin 7): enable pin. when the input voltage is higher than 1.6v, the circuit is completely turned on. when the input voltage is less than 1.3v, the circuit is turned off. pi fu ctio s uuu lo + , lo C (pins 10, 11): differential local oscillator input pins. these pins are internally biased to 2.44v. they can be driven single-ended by connecting one to an ac ground through a 1000pf capacitor. however, differential input drive is recommended to minimize lo feedthrough to the rf input pins. q out C , q out + (pins 13, 14): differential baseband output pins of the q-channel. the internal dc bias voltage is v cc C0.68v for each pin. i out C , i out + (pins 15, 16): differential baseband output pins of the i-channel. the internal dc bias voltage is v cc C0.68v for each pin. ground (pin 17, backside contact): ground return for the entire ic. this pin must be soldered to the printed circuit board ground plane. block diagra w rf + i out + lo + lo 0 /90 bias 16 i out 15 q out + 14 q out 13 lo buffers lpf i-mixer lpf q-mixer 2 5 v cc 7 en 1 gnd gnd 8 v cc 9 4 v cc 12 v cc rf 5516 bd 3 v cm 6 17 10 11 rf amp
lt5516 8 5516f test circuits i out j3 i out + j4 rf j1 q out + j5 q out j6 reference designation value size part number c1,c2,c5,c6,c7 1nf 0402 avx 04025c102jat c3 0.1 f 0402 avx 0402zd104kat c4 2.2 f 3216 avx tpsa225m010r1800 l1 33nh 0402 murata lqp10a l4 27nh 0402 murata lqp10a r1 8.2 0402 r2 100k 0402 r3 1k 0402 t1, t2 1:4 murata ldb31900m20c-416 6 t1 ldb31900m20c-416 1 l1 33nh 4 c1 1nf 2 3 5516 f02 lo j2 6 t2 ldb31900m20c-416 1 l4 27nh 4 c2 1nf 2 3 c5 1nf r1 8.2 r2 100k r3 1k en c7 1nf c6 1nf c3 0.1 f c4 2.2 f v cc lt5516 gnd rf + rf gnd v cc lo lo + v cc i out + i out q out + q out v cc v cm en v cc figure 2. 900mhz evaluation circuit schematic figure 4. component side layout of evaluation board figure 3. component side silkscreen of evaluation board
lt5516 9 5516f the lt5516 is a direct i/q demodulator targeting high linearity receiver applications, including wireless infra- structure. it consists of an rf amplifier, i/q mixers, a quadrature lo carrier generator and bias circuitry. the rf signal is applied to the inputs of the rf amplifier and is then demodulated into i/q baseband signals using quadrature lo signals. the quadrature lo signals are internally generated by precision 90 phase shifters. the demodulated i/q signals are lowpass filtered internally with a C3db bandwidth of 265mhz. the differential out- puts of the i-channel and q-channel are well matched in amplitude; their phases are 90 apart. rf input port differential drive is highly recommended for the rf inputs to minimize the lo feedthrough to the rf port and to maximize gain. (see figure 2.) a 1:4 transformer is used on the demonstration board for wider bandwidth match- ing. to assure good nf and maximize the demodulator gain, a low loss transformer is employed. shunt inductor l1, with high resonance frequency, is required for proper impedance matching. single-ended to differential conver- sion can also be implemented using narrow band, discrete l-c circuits to produce the required balanced waveforms at the rf + and rf C inputs.the differential impedance of the rf inputs is listed in table 1. table 1. rf input differential impedance frequency differential input differential s11 (mhz) impedance ( w ) mag angle (?) 800 258.7-j195.2 0.779 C16.9 900 239.9-j181.8 0.766 C18.3 1000 224.1-j170.0 0.753 C19.6 1100 210.9-j160.0 0.740 C20.9 1200 200.7-j152.1 0.729 C21.9 1300 191.4-j144.7 0.718 C23.0 1400 183.2-j138.3 0.707 C24.0 1500 176.5-j133.1 0.698 C24.9 the rf + and rf C inputs (pins 2, 3) are internally biased at 2.44v. these two pins should be dc blocked when con- nected to ground or other matching components. the rf input equivalent circuit is shown in figure 5. applicatio s i for atio wu u u an external resistor (r1) is connected to pin 6 (v cm ) to set the optimum dc current for i/q mixer linearity. the iip3 can be improved with a smaller r1 at a price of slightly higher nf and i cc . the rf performances of nf, iip3 and iip2 vs r1 are shown in the typical performance characteristics. lo input port the lo inputs (pins 10,11) should be driven differentially to minimize lo feedthrough to the rf port. this can be accomplished by means of a single-ended to differential conversion as shown in figure 2. l4, the 27nh shunt inductor, serves to tune out the capacitive component of the lo differential input. the resonance frequency of the inductor should be greater than the operating frequency. a 1:4 transformer is used on the demo board to match the 200 w on-chip resistance to a 50 w source. figure 6 shows the lo input equivalent circuit and the associated match- ing network. single-ended to differential conversion at the lo inputs can also be implemented using a discrete l-c circuit to produce a balanced waveform without a transformer. an alternative solution is a simple single-ended termina- tion. however, the lo feedthrough to rf may be degraded. either lo + or lo C input can be terminated to a 50 w source with a matching circuit, while the other input is connected to ground through a 100pf bypass capacitor. table 2 shows the differential input impedance of the lo input port. table 2. lo input differential impedance frequency differential input differential s11 (mhz) impedance ( w ) mag angle (?) 800 134.7-j65.1 0.552 C22.5 900 128.5-j66.7 0.517 C25.4 1000 121.8-j67.5 0.512 C28.5 1100 115.7-j67.2 0.505 C31.8 1200 109.3-j66.1 0.498 C35.0 1300 103.0-j64.4 0.490 C38.3 1400 96.7-j62.1 0.480 C42.0 1500 91.0-j59.4 0.469 C45.8
lt5516 10 5516f applicatio s i for atio wu u u i-channel and q-channel outputs each of the i-channel and q-channel outputs is internally connected to v cc though a 60 w resistor. the output dc bias voltage is v cc C 0.68v. the outputs can be dc coupled or ac coupled to the external loads. the differential output impedance of the demodulator is 120 w in parallel with a 5pf internal capacitor, forming a lowpass filter with a C3db corner frequency at 265mhz. r load (the single- ended load resistance) should be larger than 600 w to assure full gain. the gain is reduced by 20 ? log(1 + 120 w / r load ) in db when the differential output is terminated by r load . for instance, the gain is reduced by 6.85db when each output pin is connected to a 50 w load (100 w differ- ential load). the output should be taken differentially (or by using differential-to-single-ended conversion) for best rf performance, including nf and im2. the phase relationship between the i-channel output sig- nal and q-channel output signal is fixed. when the lo input frequency is larger (or smaller) than the rf input frequency, the q-channel outputs (q out + , q out C ) lead (or lag) i-channel outputs (i out + , i out C ) by 90 . when ac output coupling is used, the resulting highpass filters C3db roll-off frequency is defined by the r-c constant of the blocking capacitor and r load , assuming r load > 600 w . care should be taken when the demodulators outputs are dc coupled to the external load, to make sure that the i/q mixers are biased properly. if the current drain from the outputs exceeds 6ma, there can be significant degrada- tion of the linearity performance. each output can sink no more than 13ma when the outputs are connected to an external load with a dc voltage higher than v cc C 0.68v. the i/q output equivalent circuit is shown in figure 7. 3 2 rf j1 t1 ldb31900m20c-416 v cc rf + lt5516 rf 5516 f05 1k 1.54v 1.54v l1 33nh 6 2 4 1 3 c1 1nf figure 5. rf input equivalent circuit with external matching
lt5516 11 5516f applicatio s i for atio wu u u 11 10 lo j2 t2 ldb31900m20c-416 v cc lo + lo 5516 f06 200 2.44v 2.44v l4 27nh 6 2 4 1 3 c2 1nf 15 16 v cc 5pf i out + i out 5516 f07 13 14 5pf q out + q out 60 60 60 60 figure 6. lo input equivalent circuit with external matching figure 7. i/q output equivalent circuit package descriptio u uf package 16-lead plastic qfn (4mm 4mm) (reference ltc dwg # 05-08-1692) 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. 4.00 0.10 (4 sides) note: 1. drawing conforms to jedec package outline mo-220 variation (wggc) 2. all dimensions are in millimeters 3. dimensions of exposed pad on bottom of package do not include mold flash. mold flash, if present, shall not exceed 0.15mm on any side 4. exposed pad shall be solder plated pin 1 top mark 0.55 0.20 16 15 1 2 bottom view?xposed pad 2.15 0.10 (4-sides) 0.75 0.05 r = 0.115 typ 0.30 0.05 0.65 bsc 0.200 ref 0.00 ?0.05 (uf) qfn 0802 recommended solder pad pitch and dimensions 0.72 0.05 0.30 0.05 0.65 bsc 2.15 0.05 (4 sides) 2.90 0.05 4.35 0.05 package outline
lt5516 12 5516f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 l fax: (408) 434-0507 l www.linear.com ? linear technology corporation 2003 lt/tp 0503 1k printed in usa related parts part number description comments rf power controllers ltc1757a rf power controller multiband gsm/dcs/gprs mobile phones ltc1758 rf power controller multiband gsm/dcs/gprs mobile phones LTC1957 rf power controller multiband gsm/dcs/gprs mobile phones ltc4400 sot-23 rf pa controller multiband gsm/dcs/gprs phones, 45db dynamic range, 450khz loop bw ltc4401 sot-23 rf pa controller multiband gsm/dcs/gprs phones, 45db dynamic range, 250khz loop bw ltc4403 rf power controller for edge/tdma multiband gsm/gprs/edge mobile phones lt5500 rf front end dual lna gain setting +13.5db/e14db 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, 120mhz modulation bandwidth up converting mixer lt5504 800mhz to 2.7ghz rf measuring receiver 80db dynamic range, temperature compensated, 2.7v to 5.5v supply 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, e4db 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 sc70 package ltc5509 300mhz to 3ghz rf power detector 36db dynamic range, sc70 package lt5511 high signal level up converting mixer rf output to 3ghz, 17dbm iip3, integrated lo buffer lt5512 high signal level down converting mixer dc-3ghz, 20dbm iip3, integrated lo buffer

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