9-1 9 attentuators and switches product description ordering information typical applications features functional block diagram rf micro devices, inc. 7625 thorndike road greensboro, nc 27409, usa tel (336) 664 1233 fax (336) 664 0454 http://www.rfmd.com optimum technology matching? applied si bjt gaas mesfet gaas hbt si bi-cmos sige hbt si cmos 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 in gnd gnd gnd gnd gnd gnd gnd vd pd g2 g4 g8a g8b g16 out 2db 4db 8db 8db 16 db RF2410 uhf programmable attenuator ? power control in communication systems cmos compatible programmable attenuators commercial and consumer systems portable battery-powered equipment the RF2410 is a multistage monolithic programmable attenuator. the device is built using a gallium arsenide process technology and has an attenuation programma- bility over a 38db range in 2db steps. the attenuation is set by five bits of digital data. the input and output of the device have a low vswr 50 ? match. the rf output can drive up to +10dbm. this unit is intended for use in sys- tems that require rf transmit power control by digital means. a typical application is in dual mode is-54/55 compatible cellular transceivers. no negative supply volt- ages are required, and the unit has a power down feature which reduces the current consumption to less than 0.5ma. single 5v supply 0db to 38db attenuation range 4 db insertion loss 5-bit digitally controlled attenuation digitally controlled power down mode 500mhz to 2100mhz operation RF2410 uhf programmable attenuator RF2410 pcba fully assembled evaluation board 9 rev b1 010329 1 .157 .150 .393 .386 .050 .018 .014 .010 .004 .065 .043 .244 .228 8max 0min .050 .016 .010 .007 package style: sop-16
9-2 RF2410 rev b1 010329 9 attentuators and switches absolute maximum ratings parameter rating unit supply voltage -0.5 to +7.0 v dc power down voltage -0.5 to v dd +0.4 v dc operating ambient temperature -40 to +85 c storage temperature -40 to +150 c parameter specification unit condition min. typ. max. overall t=25c and 5v at 900mhz frequency range 500 to 1000 mhz 0db to 38db attenuation range frequency range 500 to 2100 mhz 0db to 20db attenuation range insertion loss 4 5.5 db attenuation range 0 to 38 db gain flatness 0.25 db in any 50mhz band input input impedance 50 ? input vswr 1.3:1 input 1db compression 10 14 dbm attenuation attenuation settings 2, 4, 8, 8, 16 db cmos level, 5 bits accuracy 1.0 2.0 3.2 db 2db step 2.9 4.0 5.4 db 4db step 6.7 8.0 9.8 db 8db step (a) 6.4 8.0 10.5 db 8db step (b) 14.1 16.0 19.3 db 16db step 35.0 38.0 42.0 db all bits on attenuation control attenuation ?on? voltage 2.5 v dd v voltage supplied to input attenuation ?off? voltage 0.3 v voltage supplied to input current 0.4 1.0 ma into each control line response time <10 ns output im3 -30 dbc with 0dbm output in each of 2 tones harmonic output -40 dbc output impedance 50 ? output vswr 1.3:1 power supply voltage 5 v specifications 4.5 to 6.0 v operating limits current 6 12 ma operating 0.4 0.75 ma power down power down power ?on? voltage 2.5 v dd v voltage supplied to input; device is ?on? power ?off? voltage 0.3 v voltage supplied to input; device is ?off? caution! esd sensitive device. rf micro devices believes the furnished information is correct and accurate at the time of this printing. however, rf micro devices reserves the right to make changes to its products without notice. rf micro devices does not assume responsibility for the use of the described product(s).
9-3 RF2410 rev b1 010329 9 attentuators and switches pin function description interface schematic 1rfin rf input. this pin is not dc blocked, and an external blocking capacitor is recommended. the value depends on the frequency used. 2gnd ground connection. keep traces physically short and connect immedi- ately to the ground plane for best performance. each ground pin should be connected to the ground plane individually, rather than using one trace and/or via for all ground pins. this will give better step accuracy. 3gnd same as pin 2. 4gnd same as pin 2. 5gnd same as pin 2. 6gnd same as pin 2. 7gnd same as pin 2. 8gnd same as pin 2. 9rfout rf output. this pin is not dc blocked, and an external blocking capac- itor is recommended. the value depends on the frequency used. 10 g16 control pin for the 16db attenuator. this pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. for operating frequencies above 1ghz this bit should always be left "off". 11 g8b control pin for the 8db attenuator. this pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. same as pin 10. 12 g8a control pin for the 8db attenuator. this pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. same as pin 10. 13 g4 control pin for the 4db attenuator. this pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. same as pin 10. 14 g2 control pin for the 2db attenuator. this pin has an internal pull-down resistor, so when the pin is not connected the attenuator will be turned off. same as pin 10. 15 pd power down control pin. this pin has an internal pull-up resistor to vdd of 10k ? . when this pin is "low" the circuits are turned off. a "low" means as close to 0v as possible, to ensure minimum current con- sumption when turned off. 16 vdd power supply pin. an external rf bypass capacitor is recommended. rf in rf out gxx pd
9-4 RF2410 rev b1 010329 9 attentuators and switches evaluation board schematic (download bill of materials from www.rfmd.com.) 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 2db 4db 8db 8db 16 db c1 100 pf c2 33 pf p1-3 p2-5 p2-4 p2-3 p2-2 p2-1 p1-1 c3 100 pf c4 33 pf j1 rf in j2 rf out 2410400 rev a 50 ? strip 50 ? strip 1 2 3 4 5 6 7 8 9 10 p2 p2-1 g2 nc nc nc nc gnd p2-5 g16 p2-4 g8b p2-3 g8a p2-2 g4 p1 1 2 3 p1-1 pd gnd p1-3 vdd
9-5 RF2410 rev b1 010329 9 attentuators and switches evaluation board layout board size 2.020? x 2.020? board thickness 0.031?, board material fr-4
9-6 RF2410 rev b1 010329 9 attentuators and switches attenuation vs. frequency 1. using all bits, 2. not using g16 ch1 s 21 logmag 5db/ ref0db start .300 000 mhz stop 3 000.000 000 mhz c2 smo ch1 s 21 logmag 5db/ ref0db start .300 000 mhz stop 3 000.000 000 mhz c2 smo RF2410 attenuation error from ideal over temperature 900 mhz desired attenuation (db) t= -40 c t= +25 c t= +85 c 2 6 10 14 10 14 18 22 18 22 26 30 26 30 34 38 -2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 2.50 3.00 error (db)
9-7 RF2410 rev b1 010329 9 attentuators and switches typical characteristics at 900mhz attenuation variation from ideal digital control setting error (db) -10 -7.5 -5 -2.5 0 2.5 2 4 6 8 10 12 14 8 10 12 14 16 18 20 22 16 18 20 22 24 26 28 30 24 26 28 30 32 34 36 38 average 5 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100 10101 10110 10111 11000 11001 11010 11011 11100 11101 11110 11111 typical attenuation error digital control setting error (db) -10 -7.5 -5 -2.5 0 2.5 5 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100 10101 10110 10111 11000 11001 11010 11011 11100 11101 11110 11111 2 4 6 8 10 12 14 8 10 12 14 16 18 20 22 16 18 20 22 24 26 28 30 24 26 28 30 32 34 36 38 500 mhz 900 mhz 1300 mhz 1700 mhz
9-8 RF2410 rev b1 010329 9 attentuators and switches
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