Add NMOS PMOS Transistors

[jClugstor]

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Add any other context about the problem here.

[ChrisRackauckas]

Add the docstring to the docs

[ChrisRackauckas]

Rebase

[ChrisRackauckas]

Rebase

[jClugstor]

I can't seem to figure out this error. I think I'm missing an import or something. If I define it on it's own it works fine:

using ModelingToolkit, ModelingToolkitStandardLibrary
using OrdinaryDiffEq
using NonlinearSolve
import ModelingToolkitStandardLibrary: Electrical.Pin, Electrical.Voltage, Electrical.Ground, Electrical.Resistor, Electrical.Capacitor, Electrical.NMOS
using ModelingToolkitStandardLibrary.Blocks: Constant
using ModelingToolkit: t_nounits as t, D_nounits as D


@mtkmodel CustomNMOS begin
    @variables begin
        V_GS(t)
        V_DS(t)
        V_OV(t)
    end


    @components begin
        d = Pin()
        g = Pin()
        s = Pin()
        b = Pin()
    end

    @parameters begin
        V_tn = 0.8
        R_DS = 1e7
        lambda = 1 / 25

        if !use_transconductance
            mu_n
            C_ox
            W
            L
        else
            k_n = 20e-3
        end

    end

    @structural_parameters begin
        use_bulk = false
        use_transconductance = true
        use_channel_length_modulation = true
    end

    begin
        if !use_transconductance
            k_n = mu_n * C_ox * (W / L)
        end
    end

    @equations begin
        V_DS ~ ifelse(d.v < s.v, s.v - d.v, d.v - s.v)
        V_GS ~ g.v - ifelse(d.v < s.v, d.v, s.v)
        V_OV ~ V_GS - V_tn

        d.i ~
            ifelse(d.v < s.v, -1, 1) * ifelse(V_GS < V_tn,
                0 + V_DS / R_DS,
                ifelse(V_DS < V_OV,
                    ifelse(use_channel_length_modulation, k_n * (1 + lambda * V_DS) * (V_OV - V_DS / 2) * V_DS + V_DS / R_DS, k_n * (V_OV - V_DS / 2) * V_DS + V_DS / R_DS),
                    ifelse(use_channel_length_modulation, ((k_n * V_OV^2) / 2) * (1 + lambda * V_DS) + V_DS / R_DS, (k_n * V_OV^2) / 2 + V_DS / R_DS)
                )
            )

        g.i ~ 0
        s.i ~ -d.i
    end
end


@mtkmodel Custom_SimpleNMOSCircuit begin
    @components begin
        Q1 = CustomNMOS(use_channel_length_modulation=false)
        Vcc = Voltage()
        Vb = Voltage()
        ground = Ground()

        Vcc_const = Constant(k=V_cc)
        Vb_const = Constant(k=V_b)
    end

    @parameters begin
        V_cc = 5.0
        V_b = 3.5
    end
    @equations begin
        #voltage sources
        connect(Vcc_const.output, Vcc.V)
        connect(Vb_const.output, Vb.V)

        #ground connections
        connect(Vcc.n, Vb.n, ground.g, Q1.s)

        #other stuff
        connect(Vcc.p, Q1.d)
        connect(Vb.p, Q1.g)
    end
end

@mtkbuild custom_sys = Custom_SimpleNMOSCircuit(V_cc=5.0, V_b=3.5)

but then when I try to use the library version which is the exact same code:

# from library
@mtkmodel SimpleNMOSCircuit begin
    @components begin
        Q1 = NMOS(use_channel_length_modulation=false)
        Vcc = Voltage()
        Vb = Voltage()
        ground = Ground()

        Vcc_const = Constant(k=V_cc)
        Vb_const = Constant(k=V_b)
    end

    @parameters begin
        V_cc = 5.0
        V_b = 3.5
    end
    @equations begin
        #voltage sources
        connect(Vcc_const.output, Vcc.V)
        connect(Vb_const.output, Vb.V)

        #ground connections
        connect(Vcc.n, Vb.n, ground.g, Q1.s)

        #other stuff
        connect(Vcc.p, Q1.d)
        connect(Vb.p, Q1.g)
    end
end

@mtkbuild custom_sys = SimpleNMOSCircuit(V_cc=5.0, V_b=3.5)

I get

ERROR: MethodError: no method matching *(::ModelingToolkit.NoValue, ::Num)
The function `*` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  *(::Any, ::Any, ::Any, ::Any...)
   @ Base operators.jl:596
  *(::ChainRulesCore.NoTangent, ::Any)
   @ ChainRulesCore ~/.julia/packages/ChainRulesCore/U6wNx/src/tangent_arithmetic.jl:64
  *(::Any, ::ChainRulesCore.NoTangent)
   @ ChainRulesCore ~/.julia/packages/ChainRulesCore/U6wNx/src/tangent_arithmetic.jl:65
  ...

Stacktrace:
 [1] 
   @ ModelingToolkitStandardLibrary.Electrical ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:918
 [2] __NMOS__
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:140 [inlined]
 [3] #_#385
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:25 [inlined]
 [4] macro expansion
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/abstractsystem.jl:1957 [inlined]
 [5] 
   @ Main ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:140
 [6] __SimpleNMOSCircuit__
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:140 [inlined]
 [7] #_#385
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/model_parsing.jl:25 [inlined]
 [8] top-level scope
   @ ~/.julia/packages/ModelingToolkit/YLJ0I/src/systems/abstractsystem.jl:1957
Some type information was truncated. Use `show(err)` to see complete types.

[ChrisRackauckas]

@ven-k can you look into this? It would be good to make the NoValue stuff throw earlier.

[ChrisRackauckas]

What's left here?

[jClugstor]

Making the NMOS or PMOS with use_channel_length_modulation = false fails.

Q1 = NMOS(use_channel_length_modulation = false, name = :no_lambda)

ERROR: MethodError: no method matching *(::ModelingToolkit.NoValue, ::Num)
The function `*` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  *(::Any, ::Any, ::Any, ::Any...)
   @ Base operators.jl:596
  *(::ChainRulesCore.NotImplemented, ::Any)
   @ ChainRulesCore ~/.julia/packages/ChainRulesCore/U6wNx/src/tangent_arithmetic.jl:37
  *(::Any, ::ChainRulesCore.NoTangent)
   @ ChainRulesCore ~/.julia/packages/ChainRulesCore/U6wNx/src/tangent_arithmetic.jl:65
  ...

Stacktrace:
 [1] 
   @ ModelingToolkitStandardLibrary.Electrical ~/.julia/packages/ModelingToolkit/aau6A/src/systems/model_parsing.jl:920
 [2] __NMOS__
   @ ~/.julia/packages/ModelingToolkit/aau6A/src/systems/model_parsing.jl:140 [inlined]
 [3] #_#402
   @ ~/.julia/packages/ModelingToolkit/aau6A/src/systems/model_parsing.jl:25 [inlined]
 [4] top-level scope
   @ REPL[2]:1
Some type information was truncated. Use `show(err)` to see complete types.

which points here https://github.com/SciML/ModelingToolkit.jl/blob/01b388a3ebdb7e00e9b1dc395f8480b645f3923d/src/systems/model_parsing.jl#L909

so it looks like something is messing up when setting defaults?

I have

 if use_channel_length_modulation
            lambda = 1 / 25, [description = "Channel length modulation coefficient (V^(-1))"]
 end

in the transistor model, since lambda isn't used if there's no channel length modulation, and use_channel_length_modulation is a structural parameter, am I using that right?

If I have just

lambda = 1 / 25, [description = "Channel length modulation coefficient (V^(-1))"]

in my parameters it does work, but then the model has an extra parameter that it doesn't use.

[ChrisRackauckas]

what's the issue with just having it zero?

[jClugstor]

Honestly we probably don't need use_channel_length_modulation as a parameter anyway. Looking at the Modelica Standard Library implementation, it doesn't have an equivalent toggle either. If a user wants to ignore the channel length effect they can just set lambda to zero.