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Programming the AD9954

Question asked by mtapalla on Jan 24, 2011
Latest reply on Feb 5, 2011 by nikmte

Hello world!

 

I am trying to follow the programming example in the AD9954 datasheet, where the part is programmed to output a 122 MHz single-tone. After sending the instruction/data bytes, and asserting the IO Update, I still don't see anything on the spectrum analyzer.

 

Here's a summary of my set-up:

Communicating with a "soft" SPI using the EZ-USB CY7C68013A.

Reset, OSK, PS0, and PS1 pins are grounded

 

I grounded Reset, OSK, PS0, and PS1 because they're not used in this scenario.

For some reason, the kit I am using has IOSYNC and IOUPDATE connected together with a pull-down 10k resistor to ground. Even if they're tied to together it shouldn't affect my commands as long as I assert IOUPDATE at the very end, correct?

 

Is there anything I can send to the AD9954 to make it reply to me so I know it's actually receiving commands correctly?

 

Thank you for your time!

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