Frequently Asked Question
What is a Direct Digital Synthesizer (DDS)?
In its simplest form, a direct digital synthesizer can be implemented from a precision reference clock, an address counter, a programmable read only memory (PROM), and a digital-to-analog converter. Direct Digital Synthesis (DDS) is a technique for using digital data processing blocks as a means to generate a frequency- and phase-tunable output signal that is referenced to a fixed-frequency precision clock source (reference clock). The reference clock frequency is “divided down” in a DDS architecture by the scaling factor set forth in a programmable binary tuning word. The tuning word is typically 24–48 bits long, which enables a DDS implementation to provide superior output frequency tuning resolution.