Quantcast
Channel: EngineerZone: Message List
Viewing all articles
Browse latest Browse all 22030

Re: HMC704LP4E, HMC835LP6GE

$
0
0

You can generate this frequency with either part using "exact frequency" mode.

 

With 10MHz reference your integer boundary is 3580MHz and desired output frequency is 10750/3 MHz=(10740+10)/3=3580MHz +10/3 MHz.

Exact frequency mode splits the frequencies between integer boundaries into equally spaced channels. If we set the number of channels to 3 (Reg0C=3) we get two equally spaced channels appearing at 1/3 and 2/3's spacing between the two integer boundaries.

Pick the first channel to get exactly 3580MHz+10/3 MHz output frequency.  You pick this channel by setting the fractional-n frequency registers to just over the desired channel frequency.

 

10(Nint+Nfrac)=3580+10/3

Nint+Nfrac=358 +1/3

Reg03=Nint=358d=0x166

Reg04=(1/3)*2E24=5592405.333

Now round up to set the fractional-n value just over the exact frequency channel:

Reg04=5592406d=0x555556

 

If you turn exact frequency mode off (Reg0C=0) the output frequency will be off by a little bit -- instead of 3583.333...MHz you will get 3583.333333730697MHz.


Viewing all articles
Browse latest Browse all 22030

Trending Articles



<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>