Rainbow Electronics RF22 - Manual (Page 50)

RF22
Version: 0.1 Date: 12/23/2008
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Figure 48. TX Unmodulated Spectrum (917 MHz) Figure 49. TX Modulated Spectrum
(917 MHz, 40 kbps, 20 kHz Deviation, GFSK)
Figure50. Synthesizer Settling Time for 1 MHz Figure 51. Synthesizer
Jump Settled within 10 kHz Phase Noise (VCOCURR = 11)
11. Application Notes
11.1. Crystal Selection
The recommended crystal parameters are given in Table 30.
Table30. Recommended Crystal Parameters
Frequency ESR CL C0 Frequency Accuracy
30 MHz 60 Ω 12 pF 5 pF ±20 ppm
The internal XTAL oscillator will work over a range for the parameters of ESR, CL, C0, and ppm accuracy. Extreme
values may affect the XTAL start-up and sensitivity of the link. For questions regarding the use of a crystal parameters
greatly deviating from the recommend values listed above, please contact customer support.
The crystal used for engineering evaluation and the reference design is the SIWARD –SX2520– 30.0 MHz – 12.0R.
Ordering number XTL581200JIG.