max2670 gps/gnss front-end amplifier ????????????????????????????????????????????????????????????????? maxim integrated products 1 functional diagram typical operating circuit appears at end of data sheet. 19-5655; rev 0; 6/11 ordering information appears at end of data sheet. for related parts and recommended products to use with this part, refer to www.maxim-ic.com/max2670.related . * without external input impedance match. ** first amplifier input is impedance matched (s 11 = -10db). second amplifier set to high gain. amplifiers cascaded without interstage filter. e v a l u a t i o n k i t a v a i l a b l e general description the max2670 gps/gnss front-end amplifier ic is designed for automotive and marine gps/gnss satellite navigation antenna modules or for any application that needs to compensate for cable losses from the antenna to receiver. two unconditionally stable low-noise amplifier stages provide the high gain and integrated i/o matching to minimize the need for external matching components and eliminate the need for additional gain stages. the device features the option to place a bandpass ceramic or saw filter between the two amplifier stages to provide a narrow-band output to further improve the noise perfor - mance of the gps/gnss receiver. additionally, a 3.4db gain step is provided to compensate for cable loss varia - tion between different applications. the device is designed to operate across all gnss fre - quency standards with a 34.8db typical cascaded gain and a 25ma supply current. the two lna stages allow the use of a wide range of gnss filter types for maxi - mum flexibility in system design. the final rf output pin, which drives the cable to the gnss receiver, is also the power-supply connection that accepts a dc supply in the 3.0v to 5.5v range. alternatively, the dc supply can be applied to pin 4. this gps/gnss front-end amplifier is designed on a low- noise, advanced sige process and is available in a lead- free, 10-pin tdfn surface-mount package (3mm x 3mm). features s first amplifier noise figure *: 1.0db s high gain**: 34.8db s 3.4db gain step s shared v cc and rfout2 pin s integrated 50 i output matching s 3.0v to 5.5v supply voltage range s small, low-cost package (3mm x 3mm) s aec-q100 qualified s esd protected to 2kv human body model applications integrated automotive and marine gps receivers active antennas 1 + 3 4 10 8 7 rfout1 dc generation gnd gain_select rfin2 gnd extcap/alt_vcc 2 9 gnd gnd 5 6 rfin1 rfout2/vcc tdfn top view amp 2 amp 1 max2670 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com.
????????????????????????????????????????????????????????????????? maxim integrated products 2 max2670 gps/gnss front-end amplifier rfout1, rfout2, extcap to gnd ....... -0.3v to (v cc + 0.5v) rfin1 input power (50 i source) .................................. +15dbm gain_select to gnd ............................. -0.3v to (v cc + 0.3v) continuous power dissipation (t a = +70 n c) tdfn (derate 18.5mw/ n c above +70 n c) .................. 1481mw operating ambient temperature range ......... -40 n c to +105 n c maximum junction temperature ..................................... +150 n c storage temperature range ............................ -65 n c to +150 n c lead temperature (soldering, 10s) ................................ +300 n c soldering temperature (reflow) ...................................... +260 n c absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional opera - tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. dc electrical characteristics (v in = 3.0v to 5.5v, t a = -40 n c to +105 n c. typical values are at +5.0v and at t a = +25 n c. pin 7 open, unless otherwise noted.) (note 1) ac electrical characteristics (v cc = 3.0v to 5.5v, p in = -40dbm, f in = 1575mhz, t a = -40 n c to +105 n c. typical values are at 5.0v and at t a = +25 n c. input matched to 50 i , load = 50 i , pin 7 open, unless otherwise noted.) (note 1) parameter symbol conditions min typ max units supply voltage v cc 3.0 5.5 v supply current i cc t a = +25 n c 15.0 25 30 ma t a = -40 n c to 105 n c 30 gain-select input current i il v il = 0v 20 100 f a parameter symbol conditions min typ max units operation frequency f rf 1575 mhz amp 1 gain | s 21 | 50 i source with no input match (note 2) 14.5 16.7 19 db 50 i source with input match 17.8 amp 1 gain variation over temperature 0.3 db amp 1 noise figure nf no input match (notes 2, 3) 1 db amp 1 input third-order intercept point iip3 two tones at 1574.5mhz and 1575.5mhz, -35dbm per tone -12 dbm amp 1 input 1db compression point 50 i source with no input match (note 2) -19 dbm amp 1 input return loss | s 11 | no input match (note 2) -4.4 db amp 1 output return loss | s 22 | -14.5 db amp 1 reverse isolation | s 12 | -33 db amp 2 gain | s 21 | 14.5 17 21 db amp 2 gain step gain change when pin 7 is shorted to gnd -2.5 -3.4 -4.0 db amp 2 gain variation over temperature 1 db amp 2 noise figure nf (note 3) 2.0 db
????????????????????????????????????????????????????????????????? maxim integrated products 3 max2670 gps/gnss front-end amplifier note 1: t a = +25 n c and t a = +105 n c are guaranteed by production test. at t a = -40 n c, the minimum and maximum values are guaranteed by design and characterization, unless otherwise noted. note 2: measured using the max2670 evaluation board with a dc-blocking capacitor at the input of lna 1. note 3: at t a = +25 n c, the maximum value is guaranteed by design and characterization. specification is corrected for board losses on the max2670 ev kit. ac electrical characteristics (continued) (v cc = 3.0v to 5.5v, p in = -40dbm, f in = 1575mhz, t a = -40 n c to +105 n c. typical values are at 5.0v and at t a = +25 n c. input matched to 50 i , load = 50 i , pin 7 open, unless otherwise noted.) (note 1) typical operating characteristics (p in = -40dbm, f in = 1575mhz, inputs and outputs are terminated to 50 i , v cc = 5.0v, t a = +25 n c, unless otherwise noted.) parameter symbol conditions min typ max units amp 2 output third-order intercept point oip3 two tones at 1574.5mhz and 1575.5mhz, -30dbm per tone 16.0 dbm amp 2 output 1db compression point 5.3 dbm amp 2 input return loss | s 11 | -21 db amp 2 output return loss | s 22 | -8.8 db amp 2 reverse isolation | s 12 | -25 db 0.6 0.8 0.7 1.0 0.9 1.1 1.2 1.3 1.4 -40 0 2 0 -20 40 60 80 100 amp 1 noise figure vs. temperature (without external input impedance match) max2670 toc01 temperature (c) noise figure (db) 1.0 2.0 1.5 3.0 2.5 3.5 4.0 4.5 5.5 5.0 -40 0 2 0 -20 40 60 80 100 amp 2 noise figure vs. temperature max2670 toc02 temperature (c) noise figure (db) low-gain mode high-gain mode 22.5 21.5 24.5 23.5 26.5 25.5 27.5 3.0 4.0 3.5 4.5 5.0 5.5 supply voltage vs. current (pin 7 open) max2670 toc03 supply voltage (v) supply current (ma) t a = +105c t a = +85c t a = +25c t a = -40c
????????????????????????????????????????????????????????????????? maxim integrated products 4 max2670 gps/gnss front-end amplifier typical operating characteristics (continued) (p in = -40dbm, f in = 1575mhz, inputs and outputs are terminated to 50 i , v cc = 5.0v, t a = +25 n c, unless otherwise noted.) 17.4 17.3 17.6 17.5 17.8 17.7 17.9 18.0 18.1 3.0 4.0 3.5 4.5 5.0 5.5 amp 1 gain vs. supply voltage (with external input impedance match) max2670 toc04 supply voltage (v) gain (db) t a = +105c t a = +85c t a = +25c t a = -40c 16.0 15.5 17.0 16.5 18.0 17.5 3.0 4.0 3.5 4.5 5.0 5.5 amp 2 gain vs. supply voltage (pin 7 open) max2670 toc05 supply voltage (v) gain (db) t a = +105c t a = +85c t a = +25c t a = -40c 13.0 12.5 12.0 14.0 13.5 15.0 14.5 3.0 4.0 3.5 4.5 5.0 5.5 amp 2 gain vs. supply voltage (pin 7 short to gnd) max2670 toc06 supply voltage (v) gain (db) t a = +105c t a = +85c t a = +25c t a = -40c 13 12 15 14 17 16 18 19 20 800 1200 1000 1400 1600 1800 2000 amp 1 gain vs. frequency (with external input impedance match) max2670 toc07 frequency (mhz) gain (db) 2 0 6 4 10 8 12 14 16 18 800 1200 1000 1400 1600 1800 2000 amp 2 gain vs. frequency max2670 toc08 frequency (mhz) gain (db) low-gain mode high-gain mode -22 -20 -21 -19 -18 -17 -16 -40 0 2 0 -20 40 60 80 100 amp 1 input p 1db vs. temperature (without external input impedance match) max2670 toc09 temperature (c) input p 1db (dbm) 4.8 5.2 5.0 5.4 5.6 5.8 -40 0 2 0 -20 40 60 80 100 amp 2 output p 1db vs. temperature (pin 7 open) max2670 toc10 temperature (c) output p 1db (db) -4.5 -5.0 -3.5 -4.0 -2.5 -3.0 -2.0 800 1200 1000 1400 1600 1800 2000 amp 1 s11 (without external input impedance match) max2670 toc11 frequency (mhz) s11 (db) -14 -16 -10 -12 -6 -8 -4 800 1200 1000 1400 1600 1800 2000 amp 1 s22 max2670 toc12 frequency (mhz) s22 (db)
????????????????????????????????????????????????????????????????? maxim integrated products 5 max2670 gps/gnss front-end amplifier typical operating characteristics (continued) (p in = -40dbm, f in = 1575mhz, inputs and outputs are terminated to 50 i , v cc = 5.0v, t a = +25 n c, unless otherwise noted.) -36 -34 -40 -38 -32 800 1200 1000 1400 1600 1800 2000 amp 1 s12 max2670 toc15 frequency (mhz) s12 (db) -15 -10 -25 -20 -5 0 800 1200 1000 1400 1600 1800 2000 amp 2 s11 max2670 toc13 frequency (mhz) s11 (db) -28 -24 -36 -40 -32 -20 800 1200 1000 1400 1600 1800 2000 amp 2 s12 max2670 toc16 frequency (mhz) s12 (db) -14 -16 -10 -12 -20 -22 -18 -6 -8 -4 800 1200 1000 1400 1600 1800 2000 amp 2 s22 max2670 toc14 frequency (mhz) s22 (db)
????????????????????????????????????????????????????????????????? maxim integrated products 6 max2670 gps/gnss front-end amplifier pin description pin configuration pin name function 1 rfin2 amplifier 2 input. incorporates an internal dc-blocking capacitor and is internally matched to 50 i . this input is designed to be connected to a bandpass filter. 2, 3, 8, 9 gnd electrical ground 4 extcap/alt_vcc external smoothing capacitor for internal supply voltage or can be used as the external dc supply pin to eliminate the need for a bias-t on rfout2/vcc. 5 rfout2/vcc amplifier 2 output. incorporates an internal dc-blocking capacitor and is internally matched to 50 i . dc bias on this pin serves as the power supply through a bias-t. 6 rfin1 amplifier 1 input. requires external dc-blocking capacitor and matching components. 7 gain_select amp 2 gain select. open is high-gain mode. short to ground is low-gain mode. 10 rfout1 amplifier 1 output. incorporates an internal dc-blocking capacitor and is internally matched to 50 i . this output is designed to drive a bandpass filter. ep exposed pad ground. the exposed pad must be soldered to the circuit board for proper thermal and electrical performance. 1 + 3 4 10 8 7 rfout1 gnd gain_select rfin2 gnd extcap/alt_vcc 2 9 gnd gnd 5 6 rfin1 rfout2/vcc ep tdfn top view max2670
????????????????????????????????????????????????????????????????? maxim integrated products 7 max2670 gps/gnss front-end amplifier detailed description the max2670 ic contains two lna stages tuned for use at 1575mhz. amp 1 amp 1 has an internal load that limits the bandwidth and provides a 50 i output impedance through a dc-blocking capacitor. the internal biasing for amp 1 suppresses gain variation with changes in temperature and supply voltage. at the input, an integrated dc-blocking capaci - tor and matching network are intentionally omitted to allow selection of external components to optimize for noise or gain. amp 2 with gain step the output of amp 2 has the dual role of providing both the rf output drive and receiving the dc power supply through a single cable. both the input and output ports of amp 2 are internally matched to 50 i impedance at 1575mhz. a 3.4db gain switch can be used to adjust the gain for different applications. the gain-select pin is connected to an inverter with an internal pullup resistor. hence, the gain-select pin is set by default to high-gain mode. shorting the gain-select pin to ground sets the gain stage to a 3.4db lower gain. as with amp 1, amp 2 has an internal load that limits the bandwidth, and the amplifiers internal biasing suppresses gain variation with changes in temperature and supply voltage. alternate supply (alt_vcc) the ic power can be supplied from the navigation sys - tem through rfout2 (pin 5). an integrated filter is con - nected to the output of lna 2 to separate the supply volt - age from the gps signal. alternatively, the supply voltage can be applied to the external capacitor pin (pin 4). layout considerations for best performance, carefully lay out the pcb using high-frequency techniques. use controlled-impedance transmission lines to interface with the max2670 high- speed inputs and outputs and isolate the input sig - nals from the output signals as much as possible. for improved noise figure, keep the connection to the input of lna 1 as short as possible. a power-supply decou - pling capacitor should be placed very close to pin 4 and connected directly to a ground plane. if low-gain selec - tion for lna 2 is required, connect pin 7 directly to the ground plane with a very short pcb trace. good ground - ing is critical for this device. the backside ground plane should be as close as possible. refer to www.maxim-ic.com for the max2670 evaluation kit schematic, gerber data, pads layout file and bom information. typical operating circuit 1 lna2 input lna1 input 2/3 4 5 6 7 8/9 10 saw v cc reg v cc reg lna 2 alt_vc c rfout2/vcc gain_select open = 31.4db gain short to ground = 28db gain exposed pad lna 1 max2670
????????????????????????????????????????????????????????????????? maxim integrated products 8 max2670 gps/gnss front-end amplifier ordering information + denotes a lead(pb)-free/rohs-compliant package. t = tape and reel. *ep = exposed pad. /v denotes automotive qualified part. package information for the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. part temp range pin-package max2670gtb+t -40 n c to +105 n c 10 tdfn-ep* max2670gtb/v+t -40 n c to +105 n c 10 tdfn-ep* package type package code outline no. land pattern no. 10 tdfn-ep t1033+2 21-0137 90-0061
max2670 gps/gnss front-end amplifier revision history maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 9 ? 2011 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision number revision date description pages changed 0 6/11 initial release
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