+ Post New Thread
Results 1 to 3 of 3
  1. #1
    Member level 1
    Points: 1,632, Level: 9
    Achievements:
    7 years registered
    xianweng's Avatar
    Join Date
    Aug 2011
    Posts
    33
    Helped
    0 / 0
    Points
    1,632
    Level
    9

    Using VCVS as delay elements result in period signal rising and falling time changing

    Hi, everyone,

    My cadence version is IC6.1.7 and MMSIM version is 13.1. I am using VCVS as delay unit (I know there are some delay component in analogLib like delayline, but there are some other strange phenomena).

    The testbench and simulation results are shown in the following figures. The gain of vcvs is 1 and delay time is 1.1us. The vpulse period is 7ms, pulse width is 800ns as shown in fig2. The result of the first period is right as shown in fig3, but the second period result is wrong as shown in fig4. The rising and falling time of fig4 are 177ns, which changed significantly. And the fourth period is right.
    Click image for larger version. 

Name:	6136.testbench.jpg-320x240.jpg 
Views:	7 
Size:	8.8 KB 
ID:	154914
    fig1. Testbench
    Click image for larger version. 

Name:	vsource.jpg-320x240.jpg 
Views:	4 
Size:	9.2 KB 
ID:	154915
    fig2. configuration of vpulse
    Click image for larger version. 

Name:	sim1.jpg-320x240.jpg 
Views:	3 
Size:	15.2 KB 
ID:	154916
    fig3. The simulation of the first period
    Click image for larger version. 

Name:	sim2.jpg-320x240.jpg 
Views:	3 
Size:	14.9 KB 
ID:	154917
    fig4. The simulation of the second period

    Any hint on that?

    Best regards,

    xianweng

    •   AltAdvertisement

        
       

  2. #2
    Full Member level 3
    Points: 1,260, Level: 8

    Join Date
    Jan 2019
    Location
    Belgium
    Posts
    183
    Helped
    74 / 74
    Points
    1,260
    Level
    8

    Re: Using VCVS as delay elements result in period signal rising and falling time chan

    Have you tried changing the maxstep parameter in your transient simulation?



    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 5
    Points: 39,470, Level: 48

    Join Date
    Mar 2008
    Location
    USA
    Posts
    6,380
    Helped
    1860 / 1860
    Points
    39,470
    Level
    48

    Re: Using VCVS as delay elements result in period signal rising and falling time chan

    I've never used the Cadence analogLib vcvs in this way.
    Are there perhaps other non-displayed params that set
    tr/tf (or slew rate)?



--[[ ]]--