+ Post New Thread
Results 1 to 14 of 14
  1. #1
    Full Member level 6
    Points: 3,237, Level: 13

    Join Date
    Aug 2005
    Location
    Shanghai
    Posts
    351
    Helped
    17 / 17
    Points
    3,237
    Level
    13

    How to get "gm" of a nmos using spectre?

    How to get "gm" of a nmos using spectre?
    I use spectre command line to simelute the circuit.

  2. #2
    Advanced Member level 2
    Points: 5,357, Level: 17
    Fom's Avatar
    Join Date
    Mar 2004
    Location
    Taiwan
    Posts
    633
    Helped
    85 / 85
    Points
    5,357
    Level
    17

    How to get "gm" of a nmos using spectre?

    Using calculator
    deriv(Id)/deriv(Vgs)



  3. #3
    Full Member level 6
    Points: 3,237, Level: 13

    Join Date
    Aug 2005
    Location
    Shanghai
    Posts
    351
    Helped
    17 / 17
    Points
    3,237
    Level
    13

    Re: How to get "gm" of a nmos using spectre?

    Quote Originally Posted by Fom
    Using calculator
    deriv(Id)/deriv(Vgs)
    1)Is there any methods to directly get gm? Just like in Hspice :
    .probe par=('gmo(mn)')

    2)How to show the "helped me" button?

    Thanks.



    •   AltAdvertisement

        
       

  4. #4
    Member level 1
    Points: 1,306, Level: 8

    Join Date
    Sep 2006
    Posts
    38
    Helped
    4 / 4
    Points
    1,306
    Level
    8

    Re: How to get "gm" of a nmos using spectre?

    in ADE window go to --results--direct plot--model parameters
    then gm of transisistor is displayed in schematic



    •   AltAdvertisement

        
       

  5. #5
    Newbie level 6
    Points: 1,416, Level: 8

    Join Date
    Mar 2006
    Posts
    12
    Helped
    0 / 0
    Points
    1,416
    Level
    8

    Re: How to get "gm" of a nmos using spectre?

    ADE
    Results -> Print -> DC Operating Points



  6. #6
    Full Member level 1
    Points: 2,556, Level: 11

    Join Date
    Nov 2006
    Posts
    99
    Helped
    5 / 5
    Points
    2,556
    Level
    11

    Re: How to get "gm" of a nmos using spectre?

    u can directly do dc simulation by saving op. point. later u can see the dc op. point for transistor where u can find gm.



    •   AltAdvertisement

        
       

  7. #7
    Newbie level 6
    Points: 1,383, Level: 8

    Join Date
    Sep 2005
    Posts
    14
    Helped
    1 / 1
    Points
    1,383
    Level
    8

    Re: How to get "gm" of a nmos using spectre?

    Quote Originally Posted by Jinkyu
    ADE
    Results -> Print -> DC Operating Points
    Yes, this is the simplest way.



  8. #8
    Full Member level 2
    Points: 2,439, Level: 11

    Join Date
    Mar 2006
    Posts
    141
    Helped
    6 / 6
    Points
    2,439
    Level
    11

    How to get "gm" of a nmos using spectre?

    I'm not sure but in Spectre we can declare the parameter and get the gm of transistor directly or go to the results and then browse to get the transistor level power screen in tht u can get the transconductance. I forgot the path,but it is from the Results menu.
    Please try, if any prob do reply.



  9. #9
    Full Member level 1
    Points: 2,084, Level: 10

    Join Date
    Feb 2007
    Location
    india
    Posts
    118
    Helped
    16 / 16
    Points
    2,084
    Level
    10

    Re: How to get "gm" of a nmos using spectre?

    gm will vary with bias current id , so gm varies with id , please follow razavi text book for this one.



  10. #10
    Advanced Member level 1
    Points: 3,359, Level: 13

    Join Date
    May 2004
    Location
    China
    Posts
    422
    Helped
    24 / 24
    Points
    3,359
    Level
    13

    How to get "gm" of a nmos using spectre?

    you can plot gm vs vgs (or Ids). THe way is to sweep vgs (or ids) and save the device's operation point( of course, gm) and do the plot.



  11. #11
    Member level 5
    Points: 2,312, Level: 11

    Join Date
    May 2006
    Posts
    86
    Helped
    3 / 3
    Points
    2,312
    Level
    11

    How to get "gm" of a nmos using spectre?

    use ADE : results=> print=> model parameters

    it is ok now



    •   AltAdvertisement

        
       

  12. #12
    Advanced Member level 1
    Points: 4,153, Level: 15

    Join Date
    Apr 2003
    Posts
    402
    Helped
    25 / 25
    Points
    4,153
    Level
    15

    How to get "gm" of a nmos using spectre?

    once you finish simulation, what you can do it to go to the simulator window and you have an option to print operating point parameters, choose this option and you can see almost all the parameters. i agree that this is not convenient for those who are used to using hspice and eldo.



  13. #13
    Member level 4
    Points: 2,775, Level: 12
    Achievements:
    7 years registered
    paley's Avatar
    Join Date
    Mar 2006
    Posts
    78
    Helped
    6 / 6
    Points
    2,775
    Level
    12

    How to get "gm" of a nmos using spectre?

    after your DC simulation, Results -> Print -> DC Operating Points is simple way



  14. #14
    Junior Member level 1
    Points: 1,063, Level: 7

    Join Date
    May 2007
    Posts
    15
    Helped
    0 / 0
    Points
    1,063
    Level
    7

    Re: How to get "gm" of a nmos using spectre?

    yes, this is the best method :D



--[[ ]]--