ATA5749 Datasheet, PDF (11/26 Pages) ATMEL Corporation – Fractional-N PLL Transmitter IC

ATA5749 [Preliminary]
5. Pulling of Frequency due to ASK Modulation (PA Switching)
The switching effect on VCO frequency in ASK Mode is very low if a correct PCB layout and
decoupling is used. Therefore, power ramping is not needed to achieve a clean spectrum (see
Figure 5-1).
Figure 5-1. Typical RF Spectrum of 40 kHz ASK Modulation at Pout = 12.5 dBm
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