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HMC830LP6GE typical doubts

Question asked by prasad.kmv on Sep 2, 2017
Latest reply on Oct 20, 2017 by dyoung1


I'm working with HMC830LP6GE. I have successfully configured the registers available in the pll and got expected results.

I h)ave gone some questions regarding this.


1. It has inbuilt 50MHz oscillator. If i give 100MHz external ref clock input what clock input it will take. For 100MHz to work do i need to power down the U3 hmc103l module???


2.)How to select VCO frequency(1.5 GHz to 3GHz) using 1:8 bits in Reg00h. As all 0's gives maximum frequency and all 1's gives min vco frequency. There is no clear cut definition for selecting in between frequencies?? Kindly share your thoughts on this.


3.)In fractional mode maximum PFD rate is determined by ( Fvco/N) or 100MHz whichever is less. What in case of Integer mode???


4.) I'm using default values for many  frequencies like 100MHz, 1GHz and 2 GHz in Reg09h Charge Pump register. I'm not able to understand whats going on inside PLL. Do i need to  set different CP for different frequencies? If yes how to choose proper CP?   Kindly explain  this briefly.


Thank you in advance.