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Issue with Level=3 MOS model in Spectre

milind123

Hi, 

    I am trying to simulate the FET model that I downloaded from the manufacturer. I have always been able to use Spice models by using the statement:

simulator lang=spice

before the model. But this time it complained on a statement:

B11 3 2 I= V(13,0)*I(V11)

It said that the master was unknown. After struggling a bit I decided to just write the model subckt as spectre syntax. I did that. For 2 .model statements inside I just put the "simulator lang=spice" statement before them and then

"simulator lang=spectre" after them

This helped the simulation to run but the FET characteristics are totally off. I know the model is fine since I simulated it in Spice. The FET characteristic is totally set by the nmos .model defined in the subcircuit. The model is a level=3 model and now I am considering whether I need to translate the model to Spectre. But I am not able to find how to translate a level=3 spice model to spectre because don't know what master name to use in the model statement.

Any guidance in this would be greatly appreciated.

Parents

  • I am using an external SPICE model and the model defines a voltage dependent capacitor as follows:

    C11 11 12 1E-12
    V11 11 0 0Vdc
    B11 3 2 I= V(13,0)*I(V11)
    E11 12 0 3 2 1
    E12 13 0 VCVS PWL(1) 12 0 -20.0,287.92 .......

    When I run this Spice model in Spectre with the statement simulator lang=spice I get the following error:

     The instance `B11' does not have a valid master.

    From the Spectre User Guide Spice compatibility section it does say that it supports SPICE behavioral sources. Why then it cannot recognize this behavioral source?

  • in reply to milind123

    I'm not sure which version of Spectre you're using, but in SPECTRE23.1 at least it fails with a different error for me, indicating that the "B" line is modelled as an IBIS source and the IBIS file is missing. From my checks, the "B" prefix is for IBIS sources in other SPICE simulators too so we have followed that when using SPICE syntax.

    If you want this to be a behavioural current source, change B11 to I11 and that should do it.

    Andrew

Reply
  • in reply to milind123

    I'm not sure which version of Spectre you're using, but in SPECTRE23.1 at least it fails with a different error for me, indicating that the "B" line is modelled as an IBIS source and the IBIS file is missing. From my checks, the "B" prefix is for IBIS sources in other SPICE simulators too so we have followed that when using SPICE syntax.

    If you want this to be a behavioural current source, change B11 to I11 and that should do it.

    Andrew

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