Hi,
we are trying to use the phase adjustment function of the ADF4356 in Integer-N mode. We tried to force the SD-Modulator to run in Integer-N mode as described here for the ADF4355: https://ez.analog.com/rf/f/q-a/110417/4355-2-phase-adjust-integer-n/333601#333601
However, after setting Muxout to "Reserved" and SD Testmodes to "0100 - SD EN with FRAC = 0" the output signal disappears and is only briefly visible while executing the Init Sequence or Frequency Update Sequence. Interestingly, when updating only R3 or R7, the signal reappears and when updating R0 or R4 it disappears again. But even when the signal is present, the phase adjustment is still not working in Integer-N mode.
Can you please confirm that this method works with the ADF4356 at all?
Best regards,Thomas
Hi Thomas,
There is a dedicated bit in ADF4356 for SDM test mode which is Reg0x03[31]. You need to enable it for phase adjust in integer mode. You can keep the MUXOUT and SD Test Mode selections for normal…
There is a dedicated bit in ADF4356 for SDM test mode which is Reg0x03[31]. You need to enable it for phase adjust in integer mode. You can keep the MUXOUT and SD Test Mode selections for normal operation, you just need to enable Reg0x03[31].
Regards,
Kudret
Hi Kudret,
thank you so much for the fast reply, everything works now with Reg0x03[31] enabled!
Best Regards,Thomas