so what's the advantage of PLL over DPLL?gliss said:A PLL is a phase locked loop. It is a circuit that generates an output signal based on the frequency of an input signal. It's usually used for clock multiplication and frequency detection. Say you have a 1Mhz clock and you want to generate a 5Mhz clock that's in sync with the 1Mhz clock.
A DLL is a delay locked loop and all that does is insert a variable delay onto an output signal based from an input signal. You can use it to put two clock lines in sync that have fallen out of sync because of skew for example.
A DPLL is a digital phase locked loop and is just a PLL implemented in an IC instead of discrete analog components. Typically these DPLLs are cheaper, more power efficient and less susceptible to noise compared to discrete PLLs.