mga-86576 1.5 C 8 ghz low noise gaas mmic amplifer data sheet features ? 1.6 db noise figure at 4 ghz ? 23 db gain at 4 ghz ? +6 dbm p 1db at 4 ghz ? single +5 v bias supply applications ? lna or gain stage for 2.4 ghz and 5.7 ghz ism bands ? front end amplifer for gps receivers ? lna or gain stage for pcn and mmds applications ? c-band satellite receivers ? broadband amplifer for instrumentation schematic diagram description avagos mga-86576 is an economical, easy-to-use gaas mmic amplifer that ofers low noise and excellent gain for applications from 1.5 to 8 ghz. the mga-86576 may be used without impedance matching as a high performance 2 db nf gain block. alternatively, with the addition of a simple series inductor at the input, the device noise fgure can be reduced to 1.6 db at 4 ghz. the circuit uses state-of-the-art phemt technology with self-biasing current sources, a source-follower interstage, resistive feedback, and on chip impedance matching networks. a patented, on-chip active bias circuit allows operation from a single +5 v power supply. cu r rent consumption is only 16 ma. these devices are 100% rf tested to assure consistent performance. surface mount ceramic package rf input 1 2 4 ground ground rf output and v d 3 mga-86576 schematic mga-86576 pkg pin connections mga-86576 pin connection rf output and v d rf input 1 3 2 4 ground ground 865 attention: observe precautions for handling electrostatic sensitive devices. esd machine model (class a) esd human body model (class 0) refer to avago application note a004r: electrostatic discharge damage and control.
2 absolute maximum ratings absolute symbol parameter units maximum [1] v d device voltage, rf output v 9 to ground v g device voltage, rf input v +0.5 to ground -1.0 p in cw rf input power dbm +13 t ch channel temperature c 150 t stg storage temperature c -65 to 150 mga-86576 electrical specifcations, t c = 25c, z o = 50 ?, v d = 5 v symbol parameters and test conditions units min. typ. max. gp power gain (|s 21 | 2 ) f = 1.5 ghz db 21.2 f = 2.5 ghz 23.7 f = 4.0 ghz 20 23.1 f = 6.0 ghz 19.3 f = 8.0 ghz 15.4 nf 50 50 noise figure f = 1.5 ghz db 2.2 f = 2.5 ghz 1.9 f = 4.0 ghz 2.0 2.3 f = 6.0 ghz 2.3 f = 8.0 ghz 2.5 nf o optimum noise figure f = 1.5 ghz db 1.6 (input tuned for lowest noise f = 2.5 ghz 1.5 fgure) f = 4.0 ghz 1.6 f = 6.0 ghz 1.8 f = 8.0 ghz 2.1 p 1db output power at 1 db gain f = 1.5 ghz dbm 6.4 compression f = 2.5 ghz 7.0 f = 4.0 ghz 6.3 f = 6.0 ghz 4.3 f = 8.0 ghz 3.8 ip 3 third order intercept point f = 4.0 ghz dbm 16.0 vswr input vswr f = 1.5 ghz 3.6:1 f = 2.5 ghz 3.3:1 f = 4.0 ghz 2.2:1 3.6:1 f = 6.0 ghz 1.4:1 f = 8.0 ghz 1.2:1 output vswr f = 1.5 ghz 2.5:1 f = 2.5 ghz 2.1:1 f = 4.0 ghz 1.7:1 f = 6.0 ghz 1.4:1 f = 8.0 ghz 1.3:1 i d device current ma 9 16 22 thermal resistance [2] : ch-c = 110c/w notes: 1. operation of this device above any one of these limits may cause permanent dam - age. 2. t c = 25c (t c is defned to be the tempera - ture at the package pins where contact is made to the circuit board).
3 mga-86576 typical performance, t c = 25c, z o = 50 ?, v d = 5 v figure 3. matched noise figure vs. frequency. figure 1. power gain vs. frequency at three tempera - tures. gain (db) 1 30.0 5.0 frequency (ghz) 4 7 10 25.0 20.0 15.0 10.0 2 3 5 6 8 9 -40c +25c +50c mga-86576 fig 1 nf (db) 1 3.5 1 frequency (ghz) 4 7 10 3 2.5 2 1.5 2 3 5 6 8 9 +50c mga-86576 fig 2 -40c +25c nf (db) 1 3.5 1 frequency (ghz) 4 7 10 3 2.5 2 1.5 2 3 5 6 8 9 mga-86576 fig 3 figure 2. 50 ? noise figure vs. frequency at three temperatures. figure 4. p 1db vs. frequency at three temperatures. figure 5. input and output vswr vs. frequency. figure 6. gain, nf 50 , and p 1db vs. temperature at 4 ghz. p 1db (dbm ) 1 10.0 0 frequency (ghz) 4 7 10 8.0 6.0 4.0 2.0 2 3 5 6 8 9 -40c +25c +50c mga-86576 fig 4 vsw r 1 4.0 1.5 frequency (ghz) 4 7 10 3.5 3.0 2.5 2.0 2 3 5 6 8 9 output mga-86576 fig 5 1.0 input gain and nf (db) -40 25 0 temperature c -20 0 5 0 20 15 10 5 -30 -10 mga-86576 fig 6 25 power gain noise figure p 1db (dbm ) p 1db 0 +5 +10 mga-86576 typical scattering parameters [3] , t c = 25c, z o = 50 ?, v d = 5 v freq. s 11 s 21 s 12 s 22 ghz mag ang db mag ang db mag ang mag ang 0.5 0.57 -21 15.5 5.99 46 -46.5 0.005 -15 0.62 -35 1.0 0.55 -30 19.8 9.72 17 -51.3 0.003 11 0.49 -47 1.5 0.54 -44 21.7 12.15 -7 -51.2 0.003 58 0.43 -57 2.0 0.52 -59 22.8 13.84 -31 -47.0 0.004 85 0.39 -68 2.5 0.48 -77 23.5 14.98 -54 -43.0 0.007 96 0.36 -79 3.0 0.43 -96 23.8 15.56 -77 -39.7 0.010 100 0.33 -92 3.5 0.37 -116 23.7 15.28 -100 -37.0 0.014 99 0.29 -105 4.0 0.30 -137 23.2 14.49 -122 -35.0 0.018 95 0.25 -118 4.5 0.24 -159 22.4 13.18 -142 -33.2 0.022 92 0.21 -130 5.0 0.19 178 21.5 11.82 -160 -31.9 0.026 89 0.19 -139 5.5 0.14 151 20.5 10.54 -177 -30.6 0.030 85 0.14 -151 6.0 0.12 129 19.2 9.14 166 -29.6 0.033 81 0.17 -151 6.5 0.10 111 18.1 8.08 156 -28.7 0.037 82 0.14 -116 7.0 0.08 91 17.5 7.48 142 -27.4 0.042 76 0.08 -158 7.5 0.08 75 16.4 6.64 129 -26.6 0.047 72 0.11 -153 8.0 0.07 64 15.5 5.99 118 -25.8 0.051 69 0.09 -151 8.5 0.06 48 14.7 5.45 107 -25.0 0.056 65 0.09 -146 9.0 0.04 31 14.0 5.03 96 -24.2 0.062 62 0.09 -140 9.5 0.02 18 13.4 4.66 86 -23.4 0.068 58 0.11 -143 10.0 0.01 93 12.7 4.33 76 -22.6 0.074 53 0.11 -154
4 mga-86576 typical noise parameters [3] , t c = 25c, z o = 50 ?, v d = 5 v frequency nf o ? opt ghz db mag. ang. r n /50 ? 1.0 2.1 0.56 27 0.43 1.5 1.6 0.54 31 0.40 2.5 1.5 0.47 40 0.36 4.0 1.6 0.38 54 0.32 6.0 1.8 0.28 77 0.28 8.0 2.1 0.22 107 0.25 [3] reference plane taken at point where leads meet body of package. figure 7. layout for mga-86576 demonstration amplifer. pcb dimensions are 1.18 inches wide by 1.30 inches high. the efects of inductance ass o ciated with the board material are easily analyzed and very predict-able. as a minimum, the circuit simulation should consist of the data sheet s-parameters and an additional circuit fle describing the plated through holes and any additional inductance associated with lead length between the device and the start of the plated through hole. to obtain a complete analysis of the entire amplifer circuit, the efects of the input and output microstriplines and bias decoupling circuits should be incorporated into the circuit fle. device connections v d and rf output (pin 3) rf and dc connections are shown in figure 8. dc power is provided to the mmic through the same pin used to obtain rf output. a 50 ? microstripline is used to connect the device to the following stage or output connector. a bias decoupling network is used to feed in v dd while simultaneously providing a dc block to the rf signal. the bias decoupling network shown in figure 8, consisting of resistor r1, a short length of high impedance microstrip - line, and bypass capacitor c1, provides the best overall performance in the 2 to 8 ghz frequency range. mga-86576 applic a tions information introduction the mga-86576 is a high gain, broad band, low noise amplifer. the use of plated through holes or an equiva - lent minimal inductance grounding technique placed precisely under each ground lead at the device is highly recom-mended. a minimum of two plated through holes under each ground lead is preferred with four being highly sug gested. a long ground path to pins 2 and 4 will add additional inductance which can cause gain peaking in the 2 to 4 ghz frequency range. this can also be accompanied by a decrease in stability. a suggested layout is shown in figure 7. the circuit is designed for use on 0.031 inch thick fr-4/g-10 epoxy glass dielectric material. printed circuit board thickness is also a major consid - eration. thicker printed circuit boards dictate longer plated through holes which provide greater undesired inductance. the par asitic inductance associated with a pair of plated through holes passing through 0.031 inch thick printed circuit board is approximately 0.1 nh, while the inductance of a pair of plated through holes passing through 0.062 inch thick board is about 0.2 nh. avago does not recommend using the mga-86576 mmic on boards thicker than 0.040 inch. 100-1000 pf c1 v dd high z 10-100 ? 27 pf 50 ? 50 ? 50 ? 50 ? 4 2 3 1 27 pf l1 r1 mga-86576 fig 8 figure 8. demonstration amplifer schematic.
5 the use of lumped inductors is not desired since they tend to radiate and cause undesired feedback. moving the bypass capacitor, c1, down the micr o stripline towards the v dd terminal, as shown in figure 9, will improve the gain below 2 ghz by trading of some high end gain. a mini - mum value of 10 ? for r1 is recommended to de-q the bias decoupling network, although 100 ? will provide the highest circuit gain over the entire 1.5 to 8 ghz frequency range. v dd will have to be increased accordingly for higher values of r1. for operation in the 2 to 6 ghz frequency range, a 10 pf capacitor may be used for dc blocking on the output micr o strip line. a larger value such as 27 pf is more appr opr i ate for operation at 1.5 ghz. table 1 provides the approx i mate inductor length for minimum noise fgure at a given frequency for the circuit board shown in figure 7. 7 volt bias for operation at higher temperatures the mga-86576 was designed primarily for 5 volt op - eration over the -25 to +50c temper a ture range. for applications requiring use to +85c, a 7 volt bias supply is recommended to minimize changes in gain and noise fgure at elevated temperature. figure 10 shows typical gain, noise fgure, and output power performance over temperature at 4 ghz with 7 volts applied. with a 7 volt bias supply, output power is increased approximately 1.5 db. other parameters are relatively unchanged from 5 volt data. s - parameter and noise parameter data for 7 volts are available upon request from avago. figure 9. complete mga-86576 demonstration amplifer. ground (pins 2 and 4) ground pins should attach directly to the backside ground plane by the shortest distance possible using the design hints suggested in the earlier section. liberal use of plated through vias is recommended. rf input (pin 1) a 50 ? microstripline can be used to feed rf to the de - vice. a blocking capacitor in the 10 pf range will provide a suitable dc block in the 2 to 6 ghz fr e quency range. although there is no voltage present at pin 1, it is highly suggested that a dc blocking capacitor be used to prevent accidental application of a voltage from a previous ampli - fer stage. with no further input matching, the mga-86576 is capable of noise fgures as low as 2 db in the 2 to 6 ghz frequency range. since o is not 50 ?, it is possible to de - sign and implement a very simple matc hing network in order to improve noise fgure and input return loss over a narrow frequency range. the circuit board layout shown in figure 7 provides an option for tuning for a low noise match anywhere in the 1.5 to 4 ghz frequency range. for optimum noise fgure perfo r mance in the 4 ghz frequency range, l1 can be a 0.007 inch diameter wire 0.080 inches in length as shown in figure 9. alternatively, l1 can be replaced by a 0.020 inch wide microstri pline whose length can be adjusted for minimum noise fgure in the 1.5 to 4 ghz frequency range. table 1. l1 length vs. frequency for optimum noise figure. frequency length ghz inches 1.5 0.70 1.8 0.60 2.1 0.50 2.4 0.40 2.5 0.30 3.0 0.20 3.7 0.10 4.0 0.05 db or de -40 25 0 temperature c -20 0 5 0 20 15 10 5 -30 -10 mga-86576 fig 10 25 power gain noise figure p 1db 85 125 figure 10. gain, nf 50 , and p 1db vs. temperature at 4 ghz with 7 volt bias supply.
package dimensions 76 package mga-86576 pkg dimensions 1.02 (0.040) .51 (0.20) 1.78 (0.070) 1.22 (0.048) .53 (0.021) 5.28 (0.208) 0.10 (0.004) typical dimensions are in millimeters (inches). part number ordering information no. of part number devices container mga-86576-tr1 1000 7" reel mga-86576-strg 100 strips for product information and a complete list of distributors, please go to our web site: www.avagotech.com vago, avago technologies, and the a logo are trademarks of avago technologies limited in the united states and other countries. data subject to change. copyright ? 2005-2008 avago technologies limited. all rights reserved. obsoletes 5989-4658en av02-0608en - april 29, 2008 printed circuit board materials most commercial applications dictate the need to use inexpe n sive epoxy glass materials such as fr-4 or g-10. unfortunately the losses of this type of material can become excessive above 2 ghz. as an example, a 0.5 inch long 50 ? microstri pline etched on fr-4 along with a blocking capacitor has a measured loss of 0.35 db at 4 ghz. the 0.35 db loss adds directly to the noise fgure of the mga-86576. the use of a low loss ptfe based dielectric material will preserve the inherent low noise of the mga -86576.
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