www.RFM.com E-mail: info@rfm.com Page 1 of 2
©2008 by RF Monolithics, Inc. RO3118E - 3/27/08
Electrical Characteristics
Characteristic Sym Notes Minimum Typical Maximum Units
Frequency (+25 °C) Absolute Frequency fC2, 3, 4, 5 317.925 318.075 MHz
Tolerance from 315.0 MHz ΔfC±75 kHz
Insertion Loss IL 2, 5, 6 1.6 2.2 dB
Quality Factor Unloaded Q QU9000
50W Loaded Q QL1500
Temperature Stability Turnover Temperature TO6, 7, 8 10 25 40 °C
Turnover Frequency fOfC
Frequency Temperature Coefficient FTC 0.032 ppm/°C2
Frequency Aging Absolute Value during the First Year |fA|1, 6 10 ppm/yr
DC Insulation Resistance between Any Two Terminals 5 1.0 MΩ
RF Equivalent RLC Model Motional Resistance RM5, 7, 9 21 Ω
Motional Inductance LM93 µH
Motional Capacitance CM2.7 fF
Shunt Static Capacitance CO5, 6, 9 2.8 pF
Test Fixture Shunt Inductance LTEST 2, 7 82 nH
Lid Symbolization 687 // YWWS
Standard Reel Quantity Reel Size 7 Inch 10 500 Pieces / Reel
Reel Size 13 Inch 3000 Pieces / Reel
• Ideal for 318 MHz Automotive-Keyless-Entry Transmitters
• Very Low Series Resistance
• Quartz Stability
• Complies with Directive 2002/95/EC (RoHS)
The RO3118E is a true one-port, surface-acoustic-wave (SAW) resonator in a surface-mount, ceramic case.
It provides reliable, fundamental-mode, quartz frequency stabilization of local oscillators operating at
approximately 318 MHz.
Absolute Maximum Ratings
Rating Value Units
Input Power Level 0 dBm
DC Voltage 12 VDC
Storage Temperature Range -40 to +125 °C
Operating Temperature Range -40 to +105 °C
Soldering Temperature (10 seconds / 5 cycles max.) 260 °C
318.0 MHz
SAW
Resonator
RO3118E
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
Notes:
1. Frequency aging is the change in fC with time and is specified at +65°C or
less. Aging may exceed the specification for prolonged temperatures
above +65°C. Typically, aging is greatest the first year after manufacture,
decreasing in subsequent years .
2. The center frequency, fC, is measured at the minimum insertion loss point,
ILMIN, with the res onator in the 50 Ω test system (VSWR ≤ 1.2:1). The
shunt inductance, LTEST, is tuned for parallel resonance with CO at fC.
Typi cally, fOSCILLATOR or fTRANSMITTER is approx imately equal to the
resonator fC.
3. One or more of the following United Sta tes patents apply: 4,454,488 and
4,616,197.
4. Typically, equipment utilizing this devic e requires emissions testing and
government app roval, which is the responsibility of the equipment
manufacturer.
5. Unless noted otherwis e, case temperature TC= +25°C±2°C.
6. The design, manufacturing process , and spec ifications of this device are
subject to change without no tice.
7. Derived mat hematically from one or more of the following directly
measured parameters: fC, IL, 3 dB bandwidth, fC versus TC, and CO.
8. Turnover temperature, TO, is the temperatur e of maximum (or turnover)
frequenc y, fO. The nomina l frequenc y at an y case te mperature, TC, may be
calculated from: f = fO[1 - FTC (TO-TC)2]. Typically oscillator TO is
approximately equal to the spec ified resonator TO.
9. This equiv alent RLC model approximates resonator performance near the
resonan t frequen cy and is provided for refer ence o nly. The capaci tanc e CO
is the static (nonmotional) capacitance between the two terminals
measured at low frequency (10 MHz) with a capacitance meter. The
measureme nt includes p arasitic cap acitanc e with "NC” pads unconne cted.
Case pa r as itic capacitance is approx imately 0.05 pF. Transducer parallel
capacitance can by calculated as: CP≈CO-0.05pF.
10. Tape and Reel Stan dard Per ANSI / EIA 481.
SM3030-6 Case
3.0 X 3.0
PbPb