HMC830 Frequency Hopping - Direct LUT ?


I'm working with the PLL VCO HMC830.

I want to use a look-up table (LUT) for manual calibration, as decribe in "Frequency Hopping with Hittite PLLVCOs Application Note" (attached) (https : // www .

It should have equivalence between the desired frequency and capacitors switches configuration (Reg 10h Register Tune VCO).

I wonder if somebody already have those data and could provide it.

Thank you very much in advance.

  • Hello again,

    We have another question: Which sequence needs to be sent in manual mode? We configure the PLL registers in the following order in manual mode:

    1 Reg 0A (bit 11 = 1 , Bypass VCO Tuning)

    2 VCO_Reg 02h K (K>1 or K=1, depending on the frequency required)

    3 Reg 05h 00 (Recommended in Datasheet)

    4 Reg 03h Integer Part

    5 Reg 04h Fractional Part

    6 VCO_Reg 00h Tuning (LUT Table data)

    Each time a frequency is set we need to program Reg 0A to remain in Manual mode.

    If we program Reg 03 (Nint) and Reg 04 (Nfrac) before VCO_Reg 02h, then the sequence does not work.

    Please, could you help us?, thank you very much.

  • 0
    •  Analog Employees 
    on Jul 9, 2015 6:01 PM

    Once autocal is turned off (Reg 0x0A[11]=1) it should stay off unless you perform a soft reset ( Reg 0x00[5]=1).  Can you read Reg 0x0A[11] during the manual tuning procedure to see if it has changed from "1" to "0"?

    Manual tuning should work when Nint and Nfrac are set before the output divider (VCO_Reg 02h).  You do not need step #3 (Reg 05h 00) since autocal is off.