DIff between DDFS and AD-PLL???

[wakaka]

ddfs and pll

Hi, I'm quite new to mixed signal.
Can i know wats the difference between All-Digital PLL and Direct Digital Frequency Synthesizer??
Normally both these Freq synthesizers are used in wat application??
Any articles or papers or design steps or design methodology to read?
thanks.

 

[khouly]

ddfs pll

DDFS : is based on lookup table or ROM and a phase interploator to scan the lookup table and get the digital words crosponding to the sinewave , and then these words passed to DAC and filter

the frequency resolution is very high and the switching speed is very high , but consumes alot of power specially the DAC

the all didital PLL is a PLL but all the block implemented in digital circuits , the filter , the oscillator everything is digital

khouly

 

[wakaka]

Meaning the DPLL is actually a PLL which can be realized in digital circuits (CMOS) rite?

And normall how to realize a DDFS? analog or digital??

 

[nhoctop]

Good papers and patents