RO2073A-6 * * * * * Ideal for 315.0 MHz Automotive-Keyless-Entry Transmitters Very Low Series Resistance Quartz Stability Surface-Mount Ceramic Case with 21 mm2 Footprint Complies with Directive 2002/95/EC (RoHS) 315.0 MHz SAW Resonator The RO2073A-6 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 fixed-frequency transmitters operating at 315.0 MHz. This SAW is designed for AM transmitters in automotive keyless-entry applications operating in the USA under FCC Part 15, in Canada under DoC RSS-210, and in Italy. Absolute Maximum Ratings Rating Value Units +0 dBm CW RF Power Dissipation (See: Typical Test Circuit) DC voltage Between Terminals Case Temperature 30 VDC -40 to +85 C 260 C Soldering Temperature (10 seconds / 5 cycles max.) SM-2 Case Electrical Characteristics Characteristic Center Frequency (+25 C) Sym Absolute Frequency Tolerance from 315.000 MHz Insertion Loss Quality Factor Temperature Stability Frequency Aging fC fC IL Unloaded Q QU 50 Loaded Q QL Turnover Temperature TO Turnover Frequency fO Frequency Temperature Coefficient FTC Absolute Value during the First Year |fA| DC Insulation Resistance between Any Two Terminals RF Equivalent RLC Model Notes 2,3,4,5 Typical 314.950 2,5,6 1.3 Maximum Units 315.050 MHz 50 kHz 2.2 dB 40 C 15,300 5,6,7 2,100 10 25 fC 6,7,8 ppm/C2 ppm/yr 0.032 10 1 5 Motional Resistance RM Motional Inductance LM Motional Capacitance CM Shunt Static Capacitance CO 5, 6, 9 LTEST 2, 7 Test Fixture Shunt Inductance Minimum 1.0 M 16 5, 7, 9 26 127.450 2.00299 2.0 Lid Symbolization (in addition to Lot and/or Date Codes) 2.3 110 H fF 2.6 pF nH 164 CAUTION: Electrostatic Sensitive Device. Observe precautions for handling. Notes: 1. 2. 3. 4. 5. 6. 7. 8. 9. Frequency aging is the change in fC 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. The center frequency, fC, is measured at the minimum insertion loss point, ILMIN, with the resonator in the 50 test system (VSWR 1.2:1). The shunt inductance, LTEST, is tuned for parallel resonance with CO at fC. Typically, fOSCILLATOR or fTRANSMITTER is approximately equal to the resonator fC. One or more of the following United States patents apply: 4,454,488 and 4,616,197. Typically, equipment utilizing this device requires emissions testing and government approval, which is the responsibility of the equipment manufacturer. Unless noted otherwise, case temperature TC = +25C2C. The design, manufacturing process, and specifications of this device are subject to change without notice. Derived mathematically from one or more of the following directly measured parameters: fC, IL, 3 dB bandwidth, fC versus TC, and CO. Turnover temperature, TO, is the temperature of maximum (or turnover) frequency, fO. The nominal frequency at any case temperature, TC, may be calculated from: f = fO [1 - FTC (TO -TC)2]. Typically oscillator TO is approximately equal to the specified resonator TO. This equivalent RLC model approximates resonator performance near the resonant frequency and is provided for reference only. The capacitance CO 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: CP CO - 0.05 pF. www.RFM.com E-mail: info@rfm.com (c)2008 by RF Monolithics, Inc. Page 1 of 2 RO2073A-6 - 1/7/10 Electrical Connections Equivalent LC Model Terminal 0.05 pF* Co = Cp + 0.05 pF NC NC Cp *Case Parasitics Terminal Rm Lm Cm Temperature Characteristics Typical Test Circuit The test circuit inductor, LTEST, is tuned to resonate with the static capacitance, CO, at FC. The curve shown on the right accounts for resonator contribution only and does not include LC component temperature contributions. fC = f O , T C = T O 0 0 -50 -50 -100 -100 -150 -150 (f-fo ) / fo (ppm) 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. -200 0 +20 +40 +60 +80 -200 -80 -60 -40 -20 Typical Circuit Land Pattern ELECTRICAL TEST To 50 From 50 Network Analyzer Network Analyzer Board T = T C - T O ( C ) 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. (4 Places) Typical Dimension: 0.010 to 0.047 inch (0.25 to 1.20 mm) Case Design The case material is black alumina with contrasting symbolization. All pads are nominally centered with respect to the base and consist of 40 to 70 microinches electroless gold on 60-350 micorinches electroless nickel. Typical Application Circuits Typical Low-Power Transmitter Application +9VDC Modulation Input 200k 47 C1 L1 (Antenna) C2 ROXXXXA Bottom View Typical Local Oscillator Application Output +VDC C1 www.RFM.com E-mail: info@rfm.com (c)2008 by RF Monolithics, Inc. Inches Dimensions 470 ROXXXXA Bottom View Millimeters RF Bypass +VDC L1 C2 RF Bypass Min Max Min Max A 5.74 5.99 0.226 0.236 B 3.73 3.99 0.147 0.157 C 1.70 2.29 0.067 0.090 D 0.94 1.10 0.037 0.043 E 0.83 1.20 0.033 0.047 F 1.16 1.53 0.046 0.060 G 0.94 1.10 0.037 0.043 H 0.43 0.59 0.017 0.023 K 0.43 0.59 0.017 0.023 M 5.08 5.33 0.200 0.210 N 0.38 0.64 0.015 0.025 P 3.05 3.30 0.120 0.130 Page 2 of 2 RO2073A-6 - 1/7/10