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.