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Set up of AD9914

Question asked by ErichNast on Jul 8, 2013
Latest reply on Jul 9, 2013 by ErichNast

We have developed a board with a AD9914 DDS on. We have written a program to set a single fixed frequency on it but do not get anything out of the DDS. The internally divided clock is is visible and is nice and clean and is exactly a 1/24th of the RF clock frequency. So we are pretty sure we think that the DDS is getting a nice clock and is clocked.

 

But something very small must be wrong still. Perhaps just a flag here or there or some setup value. Is there a simple single frequency setup program or programming steps available of something that does work on the chip ? Something very simple. Like the minimum steps to get a frequency out of the DDS.

 

We also checked the control signals between the control MPU and the DDS. They are all there and look correct. We are using the serial interface with SPI. Our clock frequency is 3.3GHz. The control processor is a STM32F407 from ST Microelectronics. It seems that the SPI clock phases are correct. The SPI clock frequency is currently 20MHz.

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