Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Need help in designing all digital pll (adpll)

Status
Not open for further replies.

jubin007

Newbie level 4
Joined
Mar 10, 2015
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
60
I am designing an ADPLL but am not getting which phase detector to use.
EXOR gate phase detector
JK Flip-flop phase detector
Digital phase frequency detector
DETDFF
moreover there remains a TDC along with it , but some papers tell that TDC alone is sufficient.
please help me understand what should be the preferred choice.
 

PD selection depends on many parameters, e.g. kind of VCO and reference input signals, can be either a bit or word signal, also intended pull and lock frequency range.
 

i am using all digital pll, so am using NCO. now i have designed two types of NCO, one using LUT and other using cordic algorithm which is controlled by a digital word(14 bit). This is why i need an ADPLL which will analyze and compare these two types of NCO. So i have selected an architecture. 1. phase freq detector (having 2 D-ff having high inputs and reference and feedback in the clocks with outputs as up and down), 2. a control logic which will clock and select up/down 3. an up-down counter- of 14 bit length which will be incremented or decremented by up/down signal and the output is the FSW which will drive the NCO. now I need to know two things.
1. whether this architecture is okay for my application.
2. i don't have any idea how to find lock in range(frequency), lock-in time and other parameters. please help me how to find this.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top