ad5292 configuration

Question

Hi Engineers, 
 
 I have some questions about configuration and operation of the AD5292. I am looking at using the AD5292 as a VCO tuner for the HMC733LC4B. I would like to control the voltage out of the AD5292 between 21V and 0V. I won't need to daisy chain multiple 5292s nor will I need to use the 20-TP memory register (I think) as just wish to be able to set the RDAC Register after power-up and change the output voltage in a human speed way like a couple times per hour. I would like to know what you all think of the design below. Will it work? If not why and how can I adjust it so it might work? 
 Thanks for the help. 
 
 Caleb

EZAutoReply · Accepted Answer

Hi, 
 
 Why is your DIN pin floating, and SYNC, SDO pin connected to GND? You have to connect these pins to a microcontroller so you can control the device via SPI communication, in which you would need the SYNC pin and DIN. You can refer to page 10 of the datasheet to know the timing characteristics. SDO also requires an external pull-up resistor. 
 
 Best Regards, Yokki)