# HMC830 Frequency Hopping - Direct LUT ?

Hello,

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 . hittite.com/content/documents/application_notes/Fast_Frequency_Hopping_Application_Note.pdf).

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.

Fast_Frequency_Hopping_Application_Note.pdf

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• Autocal will pick the best VCO and switch capacitor setting for a given frequency.  The actual location of the "jumps" vary depending on the VCO.

You can decode Reg 0x10 as follows:

Reg 0x10[7:6] VCO selection, 11b= lowest frequency)

Reg 0x10[5] don't care, may by high or low

Reg 0x10[4:0] switch capacitor setting (11111b=lowest frequency)

As you see the cause of the large jumps is the don't care bit 5.  If you create a new 7 bit number by concatenating [7:6] with [4:0] you will get a steady decrease in this number as you perform the same measurement.  But for any given frequency the number will vary from part to part.

• Autocal will pick the best VCO and switch capacitor setting for a given frequency.  The actual location of the "jumps" vary depending on the VCO.

You can decode Reg 0x10 as follows:

Reg 0x10[7:6] VCO selection, 11b= lowest frequency)

Reg 0x10[5] don't care, may by high or low

Reg 0x10[4:0] switch capacitor setting (11111b=lowest frequency)

As you see the cause of the large jumps is the don't care bit 5.  If you create a new 7 bit number by concatenating [7:6] with [4:0] you will get a steady decrease in this number as you perform the same measurement.  But for any given frequency the number will vary from part to part.

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