RF1238

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Product : SAW Filters


Features:

• Ideal Front-End Filter for 318.0 MHz Wireless Receivers
• Low-Loss, Coupled-Resonator Quartz Design
• Simple External Impedance Matching
• Rugged TO39 Hermetic Package
• Complies with Directive 2002/95/EC (RoHS)




Specifications

Rating	Value	Units
Incident RF Power	+13	dBm
DC Voltage Between Any Two Pins (Observe ESD Precautions)	±30	VDC
Case Temperature5	-40 to +85

Characteristic Symbol Minimum Typical Maximum Units Nominal Frequency at 25C Absolute Frequency fC 318.0 MHz Tolerance from 318.0 MHz DfC 80 kHz Insertion Loss IL 1.7 3.5 dB 3 dB Bandwidth BW3 500 700 800 kHz Rejection at fC - 21.4 MHz (Image) 40 50 dB at fC - 10.7 MHz (LO) 15 40 dB Ultimate 80 dB Temp. Characteristics Operating Case Temp. TC -40 +85 C Turnover Temperature TO 30 45 60 C Turnover Frequency fO fC+4 kHz Freq. Temp. Coefficient FTC 0.032 ppm/C2 Frequency Aging IfAI 10 ppm/yr External Impedance Match Series Inductance L 86 nH Shunt Capacitance (Tab Side Non Tab Side) C 6.8 on Pin 1 Side 4.7 on Pin pF




Description

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 RF1238 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) RF1238 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. RFM's advanced SAW design and fabrication technology is utilized to achieve high performance and very low loss with simple external impedance matching (not included). Quartz construction of RF1238 provides excellent frequency stability over a wide temperature range.

Ideal Front-End Filter RF1238 for 318.0 MHz Wireless Receivers Low-Loss, Coupled-Resonator Quartz Design Simple External Impedance Matching Rugged TO39 Hermetic Package Complies with Directive 2002/95/EC (RoHS)