www.rfm.com e-mail: info@rfm.com page 1 of 2 ?2008 by rf monolithics, inc. RO3156A - 3/27/08 electrical characteristics characteristic sym notes minimum typical maximum units frequency (+25 c) nominal frequency RO3156A f c 2,3,4,5 868.750 869.150 mhz RO3156A-1 868.800 869.100 RO3156A-2 868.850 869.050 tolerance from 868.95 mhz RO3156A f c 200 khz RO3156A-1 150 RO3156A-2 100 insertion loss il 2,5,6 1.2 2.0 db quality factor unloaded q q u 5,6,7 6200 50 loaded q q l 850 temperature stability turnover temperature t o 6,7,8 10 25 40 c turnover frequency f o f c khz frequency temperature coefficient ftc 0.032 ppm/c 2 frequency aging absolute value during the first year |fa| 1 <10 ppm/yr dc insulation resistance between any two terminals 5 1.0 m rf equivalent rlc model motional resistance r m 5, 6, 7, 9 14.5 motional inductance l m 18.0 h motional capacitance c m 2.0 ff shunt static capacitance c o 5, 6, 9 2.1 pf test fixture shunt inductance l test 2, 7 15.8 nh lid symbolization (in addition to lot and/or date codes) 714 // ywws ? ideal for european 868.95 mhz transmitters ? very low series resistance ? quartz stability ? surface-mount ceramic case with 21 mm 2 footprint ? complies with directive 2002/95/ec (rohs) the RO3156A is a true one-port, surface-acoustic-wave (saw) resonator in a surface-mount ceramic case. it provides reliable, fundamental-mode, quartz fr equency stabilization of fixed-frequency transmitters operating at 868.95 mhz. this saw is designed specif ically for remote-control and wireless security transmitters operating under etsi-ets 300 220 in europe and under ftz 17 tr 2100 in germany. absolute maximum ratings rating value units cw rf power dissipation +5 dbm dc voltage between terminals 30 vdc case temperature -40 to +85 c soldering temperature (10 seconds / 5 cycles max.) 260 c 868.95 mhz saw resonator RO3156A RO3156A-1 RO3156A-2 caution: electrostatic sensitive device. observe precautions for handling. notes: 1. frequency aging is the change in f c with time and is specified at +65c or less. aging may exceed the specification for prolonged temperatures above +65c. typically, aging is greatest the first year after manufacture, decreasing in subsequent years. 2. the center frequency, f c , is measured at the minimum insertion loss point, il min , with the resonator in the 50 test system (vswr 1.2:1). the shunt inductance, l test , is tuned for parallel resonance with c o at f c . typically, f oscillator or f transmitter is approximately equal to the resonator f c . 3. one or more of the following united states patents apply: 4,454,488 and 4,616,197. 4. typically, equipment utilizing this dev ice requires emissions testing and government approval, which is th e responsibility of the equipment manufacturer. 5. unless noted otherwise, case temperature t c = +25c2c. 6. the design, manufacturing process, and specifications of this device are subject to change without notice. 7. derived mathematically from one or more of the following directly measured parameters: f c , il, 3 db bandwidth, f c versus t c , and c o . 8. turnover temperature, t o , is the temperature of maximum (or turnover) frequency, f o . the nominal frequency at any case temperature, t c , may be calculated from: f = f o [1 - ftc (t o -t c ) 2 ]. typically oscillator t o is approximately equal to the specified resonator t o . 9. this equivalent rlc model approximates resonator performance near the resonant frequency and is provided for reference only. the capacitance c o is the static (nonmotional) capacitance between the two terminals measured at low frequency (10 mhz) with a capacitance meter. the measurement includes parasitic capacitance with "nc? pads unconnected. case parasitic capacitance is approximately 0.05 pf. transducer parallel capacitance can by calculated as: c p c o -0.05pf. sm5035-4
www.rfm.com e-mail: info@rfm.com page 2 of 2 ?2008 by rf monolithics, inc. RO3156A - 3/27/08 electrical connections the saw resonator is bidirectional and may be installed with either orientation. the two terminals are interchangeable and unnumbered. the callout nc indicates no internal connection. the nc pads assist with mechanical positioning and stability. external grounding of the nc pads is recommended to help reduce parasitic capacitance in the circuit. typical test circuit the test circuit inductor, l test , is tuned to resonate with the static capacitance, c o , at f c . typical application circuits equivalent lc mode l temperature characteristics the curve shown on the right accounts for resonator contribution only and does not include lc component temperature contributions. typical circuit board land pattern the circuit board land pattern shown below is one possible design. the optimum land pattern is dependent on the circuit board assembly process which varies by manufacturer. the distance between adjacent land edges should be at a maximum to minimize parasitic capacitance. trace lengths from terminal lands to other components should be short and wide to minimize parasitic series inductances. case design terminal terminal c a s e g r o u n d c a s e g r o u n d electrical test from 50 network analyzer to 50 network analyzer 50 source at f c reflected incident p p low-loss matching network to 50 terminal terminal nc nc power test cw rf power dissipation = incident - reflected p p c1 c2 l1 (antenna) +9vdc 47 rf bypass modulation input typical low-power transmitter application ro3xxxa bottom view 470 200k c1 c2 l1 output +vdc rf bypass +vdc typical local oscillator applications ro3xxxa bottom view dimensions millimeters inches min nom max min nom max a 4.87 5.0 5.13 .191 .196 .201 b 3.37 3.5 3.63 .132 .137 .142 c 1.45 1.53 1.60 .057 .060 .062 d 1.35 1.43 1.50 .040 .057 .059 e .67 .80 .93 .026 .031 .036 f .37 .50 .63 .014 .019 .024 g 1.07 1.20 1.33 .042 .047 .052 0.05 pf* 0.05 pf c p c o + = *case parasitics c p rm lm c m -80 -60 -40 -20 0 +20 +40 +60 0 -50 -100 -150 +80 -200 0 -50 -100 -150 -200 f c = f o , t c = t o t = t c - t o ( c ) (f-f o o ) / f (ppm) typical dimension: 0.010 to 0.047 inch (0.25 to 1.20 mm) (4 places) a b c d e (3x) f (4x) g (1x) top view side view bottom view 1 2 3 4
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