RFM products are now Murata products. RF1238 Ideal Front-End Filter for 318.0 MHz Wireless Receivers Pb Low-Loss, Coupled-Resonator Quartz Design Simple External Impedance Matching 318.0 MHz Rugged TO39 Hermetic Package Complies with Directive 2002/95/EC (RoHS) SAW Filter The RF1238 is a low-loss, compact, and economical surface-acoustic-wave (SAW) filter designed to provide front-end selectivity in 318.0 MHz receivers. Receiver designs using this filter include superhet with 10.7 MHz or 500 kHz IF, direct conversion and superregen. Typical applications of these receivers are wireless remote-control and security devices operating in the USA under FCC Part 15, in Canada under DoC RSS-210, and in Australia. This coupled-resonator filter (CRF) uses selective null placement to provide suppression, typically greater than 40 dB, of the LO and image spurious responses of superhet receivers with 10.7 MHz IF. Muratas advanced SAW design and fabrication technology is utilized to achieve high performance and very low loss with simple external impedance matching (not included). Quartz TO39-3 Case construction provides excellent frequency stability over a wide temperature range. Characteristic Sym Notes Minimum Typical Maximum Units f Nominal Frequency at 25C Absolute Frequency C 318.0 MHz 1, 2 f Tolerance from 318.0 MHz 80 kHz C Insertion Loss IL 1 1.7 3.5 dB BW 3 dB Bandwidth 3 1, 2 500 700 800 kHz at f - 21.4 MHz (Image) Rejection 40 50 C at f - 10.7 MHz (LO) 1 dB C 15 40 Ultimate 80 T Temp. Characteristics Operating Case Temp. -40 +85 C C T Turnover Temperature O 30 45 60 C 3, 4 f f +4 Turnover Frequency kHz O C 2 Freq. Temp. Coefficient FTC 0.032 ppm/C Frequency Aging IfAI 5 10 ppm/yr External Impedance Match Series Inductance L 86 nH 1 Shunt Capacitance (Tab Side, Non Tab Side) C 6.8 on Pin 1 Side, 4.7 on Pin 2 Side pF Lid Symbolization (in addition to Lot and/or Date Codes) RFM RF1238 CAUTION: Electrostatic Sensitive Device. Observe precautions for handling. NOTES: 1. Unless noted otherwise, all measurements are made with the filter installed in the specified test fixture which is connected to a 50 test system with VSWR 1.2:1. The test fixture L and C are adjusted for minimum insertion loss at the filter center frequency, f . Note that insertion loss, bandwidth, and passband shape c are dependent on the impedance matching component values and quality. 2. The frequency f is defined as the midpoint between the 3dB frequencies. c 3. Where noted, specifications apply over the entire specified operating temperature range. 4. The turnover temperature, T , is the temperature of maximum (or turnover) frequency, f . The nominal frequency at any case temperature, T , may be O o c 2 calculated from: f = f 1 - FTC (T -T ) . o o c 5. 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 significantly in subsequent years. 6. The design, manufacturing process, and specifications of this device are subject to change without notice. 7. One or more of the following U.S. Patents apply: 4,54,488, 4,616,197, and others pending. 8. All equipment designs utilizing this product must be approved by the appropriate government agency prior to manufacture or sale. 2010-2015 by Murata Electronics N.A., Inc. RF1238 (R) 4/6/15 Page 1 of 2 www.murata.comAbsolute Maximum Ratings Rating Value Units Incident RF Power +13 dBm DC Voltage Between Any Two Pins (Observe ESD Precautions) 30 VDC 5 -40 to +85 C Case Temperature Typical Filter Response Typical filter responses are shown below. The actual response is dependent on external impedance matching and circuit layout. Illustrated frequencies and minimum rejection for LO and IMAGE are shown only for superhet receivers with 10.7 MHz IF 0 0 dB dB -1 -10 LO -2 -20 -3 -30 -4 Minimum 3dB -40 Image Passband -5 o -50 at 25 C -6 -60 -7 -70 -8 -80 100 KHz/div 5 MHz/div Frequency Frequency Case Design Electrical Connections C G B Bottom View Pin Connection Pin 1 H Pin 2 1 Input or Output F A E 2 Output or Input Pin 33 D 3 Case Ground (3 places) J (2 places) 45 Typical Test Circuit Millimeters Inches Dimensions Min Max Min Max L L A 9.40 0.370 1 2 From 50 To 50 B 3.18 0.125 3 CC Network Network Analyzer Analyzer C 2.50 3.50 0.098 0.138 D 0.46 Nominal 0.018 Nominal E 5.08 Nominal 0.200 Nominal F 2.54 Nominal 0.100 Nominal G 2.54 Nominal 0.100 Nominal H 1.02 0.040 J 1.40 0.055 2010-2015 by Murata Electronics N.A., Inc. www.murata.com RF1238 (R) 4/6/15 Page 2 of 2 Amplitude Response Amplitude Response