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HMC821 frequency synthesizer

Question asked by Mete on Nov 12, 2015
Latest reply on Nov 23, 2015 by DonY

Hi,

We designed a PCB for @HMC821 frequency synthesizer as much as similar to the one depicted in the datasheet of HMC821. and we load registers as below to obtain 1900MHz RF at the output

 

reg02  : 00000001

reg06:  0003074a

reg09: 00003264

reg05: 0000e80d

reg05:   0000ab95

reg05: 0000d11d

reg05: 00000005

reg03: 000000be

reg04: 00000000

 

 

but we obtain in spectrum three different frequencies at approxiametly 900MHz, 1821 MHz ,and 2700MHz, although it says LOCKED.

 

We couldn't find what can cause this.

is it possible to find source code ?

 

We also have the eval board of the HMC821 but we are not able to set frequency via its interface when we use an external reference frequency of 10 MHz. I think it works only with 50 MHz reference, which is on the board.

 

We would appreciate if you suggest.

 

thank you.

 

Mete

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