Application Hint 34 Micrel Application Hint 34 MICRF002/RF011/RF022 Ceramic Resonators Ceramic Resonator Series Resistance Ceramic Resonator Availability An on-board oscillator within the MICRF002, MICRF011, and MICRF022, together with an externally connected resonator or clock signal, establishes the operating frequency of the MICRF002/RF011/RF022. When using a resonator (ceramic resonator or crystal), its series resistance should be minimized to ensure oscillation. If the resonator series resistance is too great, the oscillator may operate at a diminished peak-to-peak level or may fail to oscillate entirely. Micrel recommends that series resistance for ceramic resonators and crystals not exceed 50Ω and 100Ω, respectively. A family of ceramic resonators manufactured by Murata Electronics, featuring low series resistance, has been characterized with the MICRF011/RF022/RF002. This characterization was performed with the IC operating in “sweep” mode. These standard resonators (see table on following page) provide a convenient solution for many common frequencies. Sample quantities of standard resonators are available from Murata Electronics (www.murata.com) for rapid prototyping. Murata can also provide resonators at custom frequencies for high-volume applications. Resonator Frequency = fT = fTX 64.25 Receive Frequency Resonator Frequency Murata Part No. 315MHz 4.903MHz CST0490MGO3052 390MHz 6.07MHz CST5607MGO3052 418MHz 6.506MHz CSTS0650MGO3052 433.92MHz 6.754MHz CSTS0675MGO3052 Ceramic Resonator Samples Available Through Micrel Semiconductor Also see full table on following page. QwikRadio is a trademark of Micrel, Inc. The QwikRadio ICs were developed under a partnership agreement with AIT of Orlando, Florida Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com March 2000 1 Application Hint 34 Application Hint 34 4.747MHz 305MHz TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 2 WEB CSTS0675MGA03052 Note 5 CSTS0666MGA03052 Note 5 CSTS0650MGA03052 Note 5 CSTS0645MGA03052 Note 5 CSA6.22MGA05052 CSA6.17MGA05052 CSA6.07MGA05052 CSA6.02MGA05052 CSA4.90MGA05052 CSA4.74MGA05052 CSA4.66MGA05052 Leaded Automotive Grade (Note 3) CSA4.66MGCA05052-TC CSA4.66MGCMA05052-TC Note 4 SMD Automotive Grade (Note 3) CSTCC6.75MG03052-TC Note 6 CSTCC6.66MG03052-TC Note 6 CSTCC6.50MG03052-TC Note 6 CSTCC6.45MG03052-TC Note 6 CSTCC6.22MG03052-TC Note 6 CSTCC6.17MG03052-TC Note 6 CSTCC6.07MG03052-TC Note 6 CSTCC6.02MG03052-TC Note 6 CSTCC6.75MGA03052-TC Note 6 CSTCC6.66MGA03052-TC Note 6 CSTCC6.50MGA03052-TC Note 6 CSTCC6.45MGA03052-TC Note 6 CSTCC6.22MGA03052-TC Note 6 CSTCC6.17MGA03052-TC Note 6 CSTCC6.07MGA03052-TC Note 6 CSTCC6.02MGA03052-TC Note 6 CSAC4.90MGC05052-TC CSAC4.90MGCA05052-TC CSAC4.90MGCM05052-TC CSAC4.90MGCMA05052-TC Note 4 Note 4 CSAC4.74MGC05052-TC CSAC4.74MGCA05052-TC CSAC4.74MGCM05052-TC CSAC4.74MGCMA05052-TC Note 4 Note 4 CSAC4.66MGC05052-TC CSAC4.66MGCM05052-TC Note 4 SMD Consumer Grade (Note 2) MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 Consumer grade is for the –20˚C to +80˚C operating range and is intended for nonautomotive applications. Automotive grade, indicated by the “A” part number suffix, is for the –40˚C to +125˚C operating range and is intended for automotive applications. CSACx.xxMGCxxxxx-TC is a melph package (cylindrical package). If a round component is of a concern, Murata can recommend the CSACx.xxMGCMxxxxx-TC which adds a square plastic sleeve to the middle of the package. The square sleeve allows for automatic placement without a cylinder placement nozzle. CSTSxxxxMG(A)xxxxx is a three-terminal resonator. CAUTION: The middle terminal or lead should not be connected or grounded. CSTCCx.xxMG(A)xxxxx-TC is a three terminal resonator. CAUTION: The middle terminal should not be connected or grounded. Note 2. Note 3. Note 4. Note 5. Note 6. Murata sorts the above recommended resonators for 100% operation with the Micrel MICRF002, MICRF011, and MICRF022. Sorting insures stable oscillation and startup over resonator production variation and operating temperature range. It also insures that the specified initial oscillator frequency of the resonator will be achieved with the Micrel MICRF002, MICRF011, and MICRF022. Unsorted resonators could experience general stability problems and repeating initial oscillation frequency shifts due to the difference between the Micrel ICs and the standard resonator test circuit used in resonator production. CSTS0675MG03052 Note 5 CSTS0666MG03052 Note 5 CSTS0650MG03052 Note 5 CSTS0645MG03052 Note 5 CSA6.22MG05052 CSA6.17MG05052 CSA6.07MG05052 CSA6.02MG05052 CSA4.90MG05052 CSA4.74MG05052 CSA4.66MG05052 Leaded Consumer Grade (Note 2) Note 1. 6.754MHz 433.92MHz 6.506MHz 418MHz 6.662MHz 6.459MHz 415MHz 428.02MHz 6.226MHz 400MHz 6.176MHz 6.070MHz 390MHz 396.8MHz 6.023MHz 387MHz 4.903MHz 4.669MHz 300MHz 315MHz Resonator Frequency Receive Frequency Murata Ceramic Resonators for the Micrel MICRF002, MICRF011, and MICRF022 (Note 1) Application Hint 34 Micrel http://www.micrel.com USA This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2000 Micrel Incorporated March 2000