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 Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? 

Last post Mon, Sep 16 2013 9:17 AM by Jimmy Yu. 7 replies.
Started by Art254 19 Jul 2010 04:09 PM. Topic has 7 replies and 3590 views
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  • Mon, Jul 19 2010 4:09 PM

    • Art254
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    Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply
    Hi Everyone,

    I am transferring a diode model from ADS to Cadence. In it's ADS model, there is Imax and Ikf, I wonder what's the equivalent model parameters used in Cadence's diode in Analoglib? Please let me know.

    In ADS, Imax= explosion current beyond which diode junction current is linearized. Ikf(Ik)= high-injection knee current.

    Thank you very much.
    • Post Points: 20
  • Mon, Jul 19 2010 4:29 PM

    • Tawna
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply

     Hi Art254,

    You will want to look at the Spectre manuals for information on the diod model parameter.  For ADS model information, I suggest contacting Agilent.

    Here is a link to the Spectre manual:  (note: you must login to Cadence On Line Support to view this.)

     http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:DocumentViewer;src=pubs;q=/spectremod/spectremod7.2/Chap4.html

     

    best regards,

    Tawna

    Best regards, Tawna Wilsey Staff Support AE, Global Customer Support Cadence Design Systems, Inc.
    • Post Points: 35
  • Mon, Jul 19 2010 5:04 PM

    • Art254
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply
    Hi Tawna,

    Thank you very much for the reply. Actually, I did find the diode model parameters used in Cadence; it's in "Cadence SPICE Reference Manual". I could not find any parameters for high-injection knee current or anything close to that.

    I also compared the modeling equations used in ADS and Cadence, seems like ADS's diode equation is a bit more involved and I could not find similar equation in Cadence that's used in ADS for high-injection.

    Please let me know. Thanks.

    Art254
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  • Mon, Jul 19 2010 5:06 PM

    • Art254
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply
    Hi Tawna, By the way, in Cadence's manual, I could not find equivalent parameter to ADS's Imax as well. Art254
    • Post Points: 35
  • Mon, Jul 19 2010 10:40 PM

    • Tawna
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply

    Hi Art254,

     

    In the spectre manual that I referenced earlier:

    imelt and imax are used on devices containing p-n junctions. These devices include .... diodes....

    imax is a warning control parameter. Normally, imax does not affect the simulation results. Whenever the junction current is larger than imax, the Spectre circuit simulator issues a warning. The default value of imax is 1A, and the default value of imelt is imax. Therefore, imax can affect the simulation results only when imelt is not specified and takes its value from imax.

    And....16 ikp=`ikA/Area' High-level injection knee current for sidewall. 17 ikr=ik A/Area Reverse high-level injection knee current ( hspice compatibility flag only ).

    I cannot comment on Agilent's model, as I do not support their simulator.  You may want to put in a call to Cadence Customer Support (support.cadence.com) if you cannot find the information that you require in the Cadence Spectre Modeling Guide manual.

     

    best regards,

    Tawna

    Best regards, Tawna Wilsey Staff Support AE, Global Customer Support Cadence Design Systems, Inc.
    • Post Points: 20
  • Mon, Jul 19 2010 11:21 PM

    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply
    That's because you're looking in the Cadence SPICE manual not the spectre manual that Tawna told you to look in.

    Cadence SPICE is a rather old (and end-of-lifed) basic circuit simulator, so that's definitely not the place to look (especially if you're actually using spectre).

    Regards,

    Andrew
    • Post Points: 20
  • Tue, Jul 20 2010 1:35 PM

    • Art254
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply
    I see I see, I overlooked Tawna's "Spectre" manual. Now I got it. Thanks! Art
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  • Mon, Sep 16 2013 9:17 AM

    • Jimmy Yu
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    Re: Equivalent diode model parameter to ADS's "Imax" and "Ikf(Ik)" diode parameters? Reply

    Hi Tawna,

     You mentioned that in spectre that

    imax is a warning control parameter. Normally, imax does not affect the simulation results. Whenever the junction current is larger than imax, the Spectre circuit simulator issues a warning. The default value of imax is 1A, and the default value of imelt is imax. Therefore, imax can affect the simulation results only when imelt is not specified and takes its value from imax.

    However, my test case shows that when IMELT is defined, IMAX still affects simulation result. In my test case with IMELT=5, as IMAX is increased from  200, 2000, 20000, the diode reverse recovery current is increased from 1.7A, 2.3A and 3.6A respectively. There must be some undocumented relationship between IMAX and simulated diode current even when IMELT is specified.

     Jimmy 

    • Post Points: 5
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Started by Art254 at 19 Jul 2010 04:09 PM. Topic has 7 replies.