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AD9361 - PLL Dividers - Register '005'

Question asked by ihorev on Jun 23, 2015
Latest reply on Jun 23, 2015 by DragosB

Hello

 

I am trying to realize an application for LO changing frequency.

 

For that, i am using the BIST and transmitting an LO at 2GHz.

To here everything looks ok.

 

From here - i am trying to jump in frequency, i am using register '005' in order to change dividers (from value of 4 to 128).

Of course - i am also calculating new integer and fractional factors for the PLL.

 

My problem is in low frequencies - 100Mhz ~ 300 Mhz, or in other words: my problem rise in high PLL dividers values.

 

The spectrum looks full of spurs with many harmonies of the BIST signal.

 

 

Please advice

BR

ihorev

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