? saw filter s for amr applica tion saw flters for amr application the idt family of saw flters feature extremely low loss, high frequency selectivity and low cost, all critical to successful amr equipment design. description automated meter reading (amr) is an emerging market worldwide. using two way communications to signal and extract usage data from remote locations, amr systems require the use of saw flters to eliminate potential signal interference. typical amr applications are used to monitor usage of electricity, water and gas. idt has developed low insertion loss saw flters that are ideally suited for providing signal integrity and rejecting interference. several popular frequencies are available including 915 mhz, 868 mhz and 433 mhz. saw f eatures: ? high reliability ? insensitive to shock and vibration ? low insertion loss or high performance ? frequency stable over temperature ? flat passband ? uniform group delay ? small size ? low cost ? standard surface mount ? rohs figure 1. saw amr block diagram idt ? saw filters for amr applic ations ant lna dsp/cpu current transducer voltage transducer vco saw filter saw filter ? saw filter ?
p arameter min t yp max units c enter frequency, fc 1 C 915.3 C mhz insertion loss at fc C 1.3 2.5 db lower 3 db band e dge 2 C C 904.4 mhz upper 3 db band e dge 2 926.2 C C mhz group delay variation (904.4 to 926.2 mhz) C 40 80 ns amplitude variation (904.4 to 926.2 mhz) 1.8 3 db p-p attenuation at 894 mhz 20 25 attenuation (200 to 888.3 mhz) 2 35 C C db attenuation (888.3 to 894 mhz) 2 15 C C db attenuation (942.3 to 1400 mhz) 2 40 C C db input/o utput return loss at fc C 13 C db temperature c oeffcient of frequency C -36 C ppm/?c source/load impedance 50 50 50 ohms ambient temperature C 25 C ?c 1 defned as the average of the lower and upper 3 db frequencies at room ambient. 2 all db levels are defned relative to the insertion loss. table 1. typical amr saw flter response t ypical part number www. idt .com/go/sawflters sf0433ba02629s 433 mhz 20 mhz bw 3.8x3.8 mm sf0434ba02507s 434 mhz 4 mhz bw 3.8x3.8 mm sf0434ba02587s 434 mhz 7 mhz bw 3.8x3.8 mm sf0434ba02617s 434 mhz 2 mhz bw 3.0x3.0 mm sf0869ba02503s 869 mhz 2 mhz bw 3.8x3.8 mm sf0869ba02504s 869 mhz 3 mhz bw 3.0x3.0 mm sf0869ba02588s 869 mhz 2 mhz bw 3.0x3.0 mm sf0869ba02618s 869 mhz 20 mhz bw 3.0x3.0 mm sf0915ba03171s 915 mhz 21.8 mhz bw 3.8x3.8 mm SF0915BA02531S 915 mhz 26 mhz bw 2.5x2.0 mm sf0915ba02620s 914.5 mhz 8 mhz bw 3.8x3.8 mm table 2. amr system application part numbers p arameter min max units storage temperature range -40 85 ?c o perating temperature range -20 75 ?c input p ower level C +15 dbm figure 2. typical amr saw flter response figure 3. typical wideband response ? ? 2008 integrated device technology, inc. all rights reserved. product specifcations subject to change without notice. idt and the idt logo are registered trademarks of integrated device technology, inc. all other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. printed in usa 9-08/mg/bwd/v4_ff flyr-saw-amr-098 www.idt.com/go/sawfilters contact and t echnical support: sawhelp@ idt .com
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