The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines. Mar 24th, 2017, 10:48pm
  HomeHelpSearchLoginRegisterPM to admin  
 
Pages: 1
Send Topic Print
Characterization of time-based circuit PFD/TDC (Read 50 times)
deba
Community Member
***
Offline



Posts: 51

Characterization of time-based circuit PFD/TDC
Mar 14th, 2017, 6:36am
 
Hi,

For characterizing the dynamic non-linearity of PFD or TDC(so as to calculate SNDR, HD etc), how does one generate two phase shifted signal such that the delay between them varies in a sinusoidal manner. I want to create a verilog-A model for doing this.

Thanks
Back to top
 
 
View Profile   IP Logged
Ken Kundert
Global Moderator
*****
Offline

The Spectre

Posts: 2008
Silicon Valley
Re: Characterization of time-based circuit PFD/TDC
Reply #1 - Mar 14th, 2017, 9:06am
 
Perhaps something like this ...

Code:
module gen(out1, out2)
parameter real tclk=1u from (0:inf);
parameter real freq=1k from (0:inf);
parameter real deltat=500n from (0:tclk);
parameter real tt=10n from (0:inf);
parameter real vout=1;
real o1;

analog begin
    @(timer(0, tclk/2)) begin
	  if (o1 > vout/2)
		o1 = 0;
	  else
		o1 = vout
    end
    V(out1) <+ transition(o1, 0, tt);
    V(out2) <+ transition(o1, tclk + deltat*sin(6.14*freq*$abstime), tt);
end
endmodule
 


I have not actually tried it, but it should be close.

-Ken
Back to top
 
 
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Trouble viewing this site? Copyright © 2002-2014 Designer's Guide Consulting. 'Designer's Guide' is a registered trademark of Designer's Guide LLC. All rights reserved.
Give back to the Designer's Guide Community by shopping at Amazon. Purchasing products through this link helps to fund our activities and does not increase your cost.

Our colleges are not as safe as they seem. Sexual assault is pervasive and the treatment of the victim by the adminstration is often as damaging as the assault: Campus Survivors, Campus Survivors Forum.