LIBRARY

Analog.Semiconductors.Tests.NPNOperatingPoint

Forward-active operating-point check for NPN.

The base is held at 0.65 V through 10 Ohm and the collector at 5 V. Values from the Ebers-Moll equations at the default MSL card (Is = 1e-16, Bf = 50, Br = 0.1, Vak = 0.02, Vt = 0.02585, temperature dependency off):

I_CC = Is*(exp(0.65/Vt) - 1) + 0.65*Gbe  = 8.32461e-6
I_EC = Is*(exp(-4.35/Vt) - 1) - 4.35*Gbc = -4.450e-15
qbk  = 1 - V_BC*Vak                      = 1.087
i_c  = (I_CC - I_EC)*qbk - I_EC/Br       = 9.04886e-6

The simulated value is 9.04827e-6. The 6.4e-5 relative gap is the 10 Ohm base drop: i_b*10 = 1.66 µV, and 1.66e-6/Vt = 6.4e-5. The base resistor is not optional — an ideal source across the junction sits across C_jE, which is structurally singular.

qbk = 1.087 is the Early factor, so it contributes the 8.7% excess over I_CC.

Usage

ElectricalComponents.Analog.Semiconductors.Tests.NPNOperatingPoint(Vbase=0.65, Vcollector=5.0)

Parameters:

Name	Description	Units	Default value
Vbase	Base bias	V	0.65
Vcollector	Collector bias	V	5.0

Behavior

Source

"""
Forward-active operating-point check for NPN.

The base is held at 0.65 V through 10 Ohm and the collector at 5 V. Values from the
Ebers-Moll equations at the default MSL card (`Is = 1e-16`, `Bf = 50`, `Br = 0.1`,
`Vak = 0.02`, `Vt = 0.02585`, temperature dependency off):

```
I_CC = Is*(exp(0.65/Vt) - 1) + 0.65*Gbe  = 8.32461e-6
I_EC = Is*(exp(-4.35/Vt) - 1) - 4.35*Gbc = -4.450e-15
qbk  = 1 - V_BC*Vak                      = 1.087
i_c  = (I_CC - I_EC)*qbk - I_EC/Br       = 9.04886e-6
```

The simulated value is 9.04827e-6. The 6.4e-5 relative gap is the 10 Ohm base drop:
`i_b*10 = 1.66 µV`, and `1.66e-6/Vt = 6.4e-5`. The base resistor is not optional — an
ideal source across the junction sits across `C_jE`, which is structurally singular.

`qbk = 1.087` is the Early factor, so it contributes the 8.7% excess over `I_CC`.
"""
test component NPNOperatingPoint
  "Base level"
  base_sig = BlockComponents.Sources.Constant(k = Vbase) {
    "Dyad": {"placement": {"diagram": {"x1": 20, "x2": 120, "y1": 120, "y2": 220}}}
  }
  "Base source"
  vb = ElectricalComponents.Analog.Sources.VoltageSource() {
    "Dyad": {"placement": {"diagram": {"x1": 155, "x2": 255, "y1": 225, "y2": 325}}}
  }
  "Small base series resistance; keeps the drive off `C_jE`"
  rb = ElectricalComponents.Analog.Basic.Resistor(R = 10) {
    "Dyad": {"placement": {"diagram": {"x1": 295, "x2": 395, "y1": 435, "y2": 535}}}
  }
  "Collector level"
  col_sig = BlockComponents.Sources.Constant(k = Vcollector) {
    "Dyad": {"placement": {"diagram": {"x1": 150, "x2": 250, "y1": 20, "y2": 120}}}
  }
  "Collector source"
  vc = ElectricalComponents.Analog.Sources.VoltageSource() {
    "Dyad": {"placement": {"diagram": {"x1": 295, "x2": 395, "y1": 125, "y2": 225}}}
  }
  "Transistor under test, default card"
  q = ElectricalComponents.Analog.Semiconductors.NPN() {
    "Dyad": {"placement": {"diagram": {"x1": 425, "x2": 525, "y1": 435, "y2": 535}}}
  }
  "Ground reference"
  ground = ElectricalComponents.Analog.Basic.Ground() {
    "Dyad": {"placement": {"diagram": {"x1": 430, "x2": 530, "y1": 230, "y2": 330}}}
  }
  "Base bias"
  parameter Vbase::Voltage = 0.65
  "Collector bias"
  parameter Vcollector::Voltage = 5.0
relations
  "Started at the operating point, so the junction states carry no transient"
  initial q.V_BE = 0.65
  connect(base_sig.y, vb.V) {"Dyad": {"edges": [{"S": 1, "M": [{"x": 205, "y": 170}], "E": 2}], "path": {}}}
  connect(col_sig.y, vc.V) {"Dyad": {"edges": [{"S": 1, "M": [{"x": 345, "y": 70}], "E": 2}], "path": {}}}
  connect(vb.p, rb.p) {
    "Dyad": {
      "edges": [{"S": 1, "M": [{"x": 140, "y": 275}, {"x": 140, "y": 485}], "E": 2}],
      "path": {}
    }
  }
  connect(rb.n, q.b) {"Dyad": {"edges": [{"S": 1, "M": [], "E": 2}], "path": {}}}
  connect(vc.p, q.c) {
    "Dyad": {
      "edges": [
        {
          "S": 1,
          "M": [{"x": 280, "y": 175}, {"x": 280, "y": 380}, {"x": 475, "y": 380}],
          "E": 2
        }
      ],
      "path": {}
    }
  }
  connect(q.e, q.s, vb.n, vc.n, ground.g) {
    "Dyad": {
      "edges": [
        {
          "S": 1,
          "M": [{"x": 475, "y": 550}, {"x": 540, "y": 550}, {"x": 540, "y": 485}],
          "E": 2
        },
        {
          "S": 2,
          "M": [{"x": 550, "y": 485}, {"x": 550, "y": 600}, {"x": 270, "y": 600}],
          "E": -1
        },
        {"S": -1, "M": [], "E": 3},
        {"S": -1, "M": [{"x": 410, "y": 275}], "E": -2},
        {"S": -2, "M": [], "E": 4},
        {"S": -2, "M": [{"x": 480, "y": 175}], "E": 5}
      ],
      "junctions": [{"x": 270, "y": 275}, {"x": 410, "y": 175}],
      "path": {}
    }
  }
metadata {
  "Dyad": {
    "tests": {
      "case1": {
        "stop": 0.000001,
        "atol": {"q.c.i": 2e-8},
        "expect": {"final": {"q.c.i": 0.0000090483}}
      }
    }
  }
}
end

Flattened Source

"""
Forward-active operating-point check for NPN.

The base is held at 0.65 V through 10 Ohm and the collector at 5 V. Values from the
Ebers-Moll equations at the default MSL card (`Is = 1e-16`, `Bf = 50`, `Br = 0.1`,
`Vak = 0.02`, `Vt = 0.02585`, temperature dependency off):

```
I_CC = Is*(exp(0.65/Vt) - 1) + 0.65*Gbe  = 8.32461e-6
I_EC = Is*(exp(-4.35/Vt) - 1) - 4.35*Gbc = -4.450e-15
qbk  = 1 - V_BC*Vak                      = 1.087
i_c  = (I_CC - I_EC)*qbk - I_EC/Br       = 9.04886e-6
```

The simulated value is 9.04827e-6. The 6.4e-5 relative gap is the 10 Ohm base drop:
`i_b*10 = 1.66 µV`, and `1.66e-6/Vt = 6.4e-5`. The base resistor is not optional — an
ideal source across the junction sits across `C_jE`, which is structurally singular.

`qbk = 1.087` is the Early factor, so it contributes the 8.7% excess over `I_CC`.
"""
test component NPNOperatingPoint
  "Base level"
  base_sig = BlockComponents.Sources.Constant(k = Vbase) {
    "Dyad": {"placement": {"diagram": {"x1": 20, "x2": 120, "y1": 120, "y2": 220}}}
  }
  "Base source"
  vb = ElectricalComponents.Analog.Sources.VoltageSource() {
    "Dyad": {"placement": {"diagram": {"x1": 155, "x2": 255, "y1": 225, "y2": 325}}}
  }
  "Small base series resistance; keeps the drive off `C_jE`"
  rb = ElectricalComponents.Analog.Basic.Resistor(R = 10) {
    "Dyad": {"placement": {"diagram": {"x1": 295, "x2": 395, "y1": 435, "y2": 535}}}
  }
  "Collector level"
  col_sig = BlockComponents.Sources.Constant(k = Vcollector) {
    "Dyad": {"placement": {"diagram": {"x1": 150, "x2": 250, "y1": 20, "y2": 120}}}
  }
  "Collector source"
  vc = ElectricalComponents.Analog.Sources.VoltageSource() {
    "Dyad": {"placement": {"diagram": {"x1": 295, "x2": 395, "y1": 125, "y2": 225}}}
  }
  "Transistor under test, default card"
  q = ElectricalComponents.Analog.Semiconductors.NPN() {
    "Dyad": {"placement": {"diagram": {"x1": 425, "x2": 525, "y1": 435, "y2": 535}}}
  }
  "Ground reference"
  ground = ElectricalComponents.Analog.Basic.Ground() {
    "Dyad": {"placement": {"diagram": {"x1": 430, "x2": 530, "y1": 230, "y2": 330}}}
  }
  "Base bias"
  parameter Vbase::Voltage = 0.65
  "Collector bias"
  parameter Vcollector::Voltage = 5.0
relations
  "Started at the operating point, so the junction states carry no transient"
  initial q.V_BE = 0.65
  connect(base_sig.y, vb.V) {"Dyad": {"edges": [{"S": 1, "M": [{"x": 205, "y": 170}], "E": 2}], "path": {}}}
  connect(col_sig.y, vc.V) {"Dyad": {"edges": [{"S": 1, "M": [{"x": 345, "y": 70}], "E": 2}], "path": {}}}
  connect(vb.p, rb.p) {
    "Dyad": {
      "edges": [{"S": 1, "M": [{"x": 140, "y": 275}, {"x": 140, "y": 485}], "E": 2}],
      "path": {}
    }
  }
  connect(rb.n, q.b) {"Dyad": {"edges": [{"S": 1, "M": [], "E": 2}], "path": {}}}
  connect(vc.p, q.c) {
    "Dyad": {
      "edges": [
        {
          "S": 1,
          "M": [{"x": 280, "y": 175}, {"x": 280, "y": 380}, {"x": 475, "y": 380}],
          "E": 2
        }
      ],
      "path": {}
    }
  }
  connect(q.e, q.s, vb.n, vc.n, ground.g) {
    "Dyad": {
      "edges": [
        {
          "S": 1,
          "M": [{"x": 475, "y": 550}, {"x": 540, "y": 550}, {"x": 540, "y": 485}],
          "E": 2
        },
        {
          "S": 2,
          "M": [{"x": 550, "y": 485}, {"x": 550, "y": 600}, {"x": 270, "y": 600}],
          "E": -1
        },
        {"S": -1, "M": [], "E": 3},
        {"S": -1, "M": [{"x": 410, "y": 275}], "E": -2},
        {"S": -2, "M": [], "E": 4},
        {"S": -2, "M": [{"x": 480, "y": 175}], "E": 5}
      ],
      "junctions": [{"x": 270, "y": 275}, {"x": 410, "y": 175}],
      "path": {}
    }
  }
metadata {
  "Dyad": {
    "tests": {
      "case1": {
        "stop": 0.000001,
        "atol": {"q.c.i": 2e-8},
        "expect": {"final": {"q.c.i": 0.0000090483}}
      }
    }
  }
}
end

Test Cases

Test Case case1

Related

• Examples

• Experiments

• Analyses

• Tests

  • Constant

  • Ground

  • NPN

  • Resistor

  • VoltageSource