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On 16/03/2021 21:54, Kenneth Williams wrote:
Yes, I caught the issue that this chip is designed for two-tone FSK. However, after thinking about your idea, it is not clear that this would work without knowing the undocumented internals of the chip. Very specifically, it is not clear that if both F1 and F2 hold the same frequency, that there would be no phase discontinuity when flipping the FSK input.Ken,
the DDS is phase continuous when doing FSK frequency shifts. The ramping can be disabled in ramped-FSK mode by clearing the TRIANGLE bit if necessary. I did say that any F1/F2 swapping would need to be done in dwell time mid-symbol, probably just prior as at mid-symbol in ramped-FSK mode it is time to flip the FSK input to start the next frequency change if there is one. So I don't think any of your questions above are relevant or unanswered by the data sheet.