How do ADI's DDS engines compare to FPGA-based DDS engines?

Document created by sitti on Mar 28, 2014
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Q: How do ADI’s DDS engines compare to FPGA-based DDS engines?

A: ADI’s high-speed DDSs employ a proprietary angle-to-amplitude computation engine and digital architecture that significantly reduces power consumption without sacrificing performance. In addition, because ADI is a world leader in state-of-the-art converters, there is an added benefit of getting a leading-edge DAC as an integrated element within the DDS. That means, DDS has better spurious performance due to optimized DDS core and integrated DAC.

FPGA-based DDS engines require using an FPGA plus discrete DAC. Phase-to-amplitude conversion in most FPGAs is done with a lookup table, requiring a very large amount of resources or memory cells. In addition, the designer needs to know the subtle trade-offs and DDS architecture to optimally pair an off-the-shelf DAC with the FPGA. SFDR and noise floor can degrade depending on selection of the DAC.

As a conclusion, ADI complete DDS products have evolved a large number of features which don’t all exist in FPGA DDS engines, for example:  Shift-keying through stored profiles, auxiliary accumulators enabling frequency/phase and amplitude sweeps as well as programmable modulus capability.



This FAQ was generated from the following discussion: How do ADI's DDS engines compare to FPGA-based DDS engines?