mm , this topic is soo long , and very interesting
the DPLL : digital PLL is the where some blocks are digital and some are analog " the PFD , the divider " digital and the CP and the VCO and the loop filter are analog , the most commonly
the LPLL is all analog one , even the phase detctor is a multiplier "something like gilbert cell" ,
ADPLL : is the All digital , everything is digital the loop filter the VCO the dividers
this is still limited to low frequency , and the architectures of it , still immature and need to be more studied in the Z domain
khouly