[sdiy] DDS was Re: PIC-based Digital Oscillator question

[Tom Wiltshire]

> IS DDS the same as wavetable?
> 
> I didn't start hearing DDS until recently when I started using the Arduino and looking for ways to make oscillators.
> 
> thanks!

"DDS" (Direct Digital Synthesis) seems to be the term used for standalone chips that do this job, and like Gordon said, these tend to be aimed at RF applications. The technique they use to generate their frequencies I'd call an "NCO" (Numerically controlled oscillator), and if I was writing my webpage today, I'd have called it 'nco' not 'dds'.

Some people make a distinction between an NCO being the digital oscillator part, and if you add a optional waveform table and a DAC, so it has an analog output, it becomes a DDS. This is reasonable enough too, but you won't find a real consensus over this terminology.

T.