Ask about VCO of ADF7021-N

How to set the external VCO of ADF7021-N? Set the receiving frequency of 7021 to 149.85MHZ. The transmitting frequency is 401.95 MHZ. What is the frequency of VCO? Thank you

  • Hi,

    For 149.82MHz, use L3 of 14nH to 17nH, with the following register settings,

    R1_DB25 = 1 (this sets the VCO to external VCO)

    R1_DB18 = 1

    R1_DB[23:24] = XX

    R1_DB[19:22] = 2

    For 401.9MHz, use L3 of 6nH to 8nH, with the following register settings,

    R1_DB25 = 1 (this sets the VCO to external VCO)

    R1_DB18 = 0

    R1_DB[23:24] = XX

    R1_DB[19:22] = 3

    For your last question, do you mean frequency of VCO without dividing by 2?