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LMK04832EVM: LMK04832

Part Number: LMK04832EVM

Hi,

My request to get lower frequency about 2.5 Mhz  using the LMK04832.

At the BOM list of the LMK04832EVB  the VCOs frequencies are:  1- 800Mhz up to  1030Mhz         2 - 1800Mhz  up to 2200Mhz .

The schematics indicates that the basic VCO frequency in the PLL is 2942.19Mhz  using reference VCXO =122.88Mhz .

Each  of the 14 outputs  can be divided  by 1 up to 1023  . It means i can get  minimum  frequency of 2942.19\1024=2.87Mhz .

Are my calculations right?

What are the relations between the 2 VCOs  listed in the BOM list  to the  2942.19Mhz ??

Thanks in advance

Moshe Namer

  • Hi Moshe,

    I believe the listed VCO BOM frequencies are for optional external VCOs, which are not populated. The internal VCO frequencies for PLL2 are listed in the datasheet:

    1. VCO0 - 2440 to 2580 MHz
    2. VCO1 - 2945 to 3255 MHz

    To get 2.5 Mhz, you can use a 100 MHz VCXO (or some common multiple of 2.5 MHz), set the VCO0 frequency to 2500 MHz by configuring the N-divider to the appropriate divide, and then set the output divider to 1000.

    Regards,