Efabless Logo
digital phase...
public project

Project Title:

 CMOS digital phase and  frequency difference detector.


A phase frequency detector works on the logic which compares the phase of two input signals. It is an asynchronous circuit which is made up of four flip-flops.

It not only produces output when the input signals have phase difference but also produces the output when the signals have frequency difference.

Design Goals:

  • To design a phase and frequency detector for two different signals.
  • To determine whether there is any phase or frequency error in between input and output signals.
  • Therefore, by detecting the error we came to know what is the change that the circuit or channel where the input signal is given was altering the phase or frequency of input signal.

Block diagram of design:

 here we use flipflops and xor gate or nand gates and multiplexers. In the block diagram there are two flipflops are give connected to clocks and two different inputs and the output side of flip flops are connected to nand gate and the then the output is give as feedback to flipflops


Schematic Diagram:

here the gates and flip flops are constructed using cmos transistors so the schematic will be having gates of cmos transistors



  1. https://en.wikipedia.org/wiki/Phase_detector#References


  1. https://analog.intgckts.com/phase-locked-loop/phase-       frequency-detector/


  1. Electronic Circuits: Linear/Analog Louis E. Frenzel Jr., in Electronics Explained (Second Edition), 2018.


  1. CMOS phase frequency detector for high-speed applications.



Team members:

Mangalapally Naveen Kumar.

Bommakanti Pravali.

If you are collaborating on this project, please click here to access your collaboration files, and click "Accept Share" in the actions column if you haven't done so already.


Our project is mainly based on the phase and frequency difference detection between I/O digital signals or any two different signals.