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AD9552 not getting programmed with SPI

Question asked by goal on Mar 26, 2012
Latest reply on Mar 27, 2012 by neilw

Hi,

 

I am using AD9552 for my application. I am able to control manully the Y's and A's are could see 77/56 MHz at the output of AD9552.

I want to use SPI interface to change the frequency accordingly. I made all the Y's and A's depop since the chip has 100K pull up.

but not able to program AD9552. I am writing the register and when i try to read i am getting all zeros. Is there anything i am missing here? And also please note that i am using a 20MHz crystal and REF is connected to VDD through 100K.

 

Thanks

Prasanthi

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