modelCjD

Spice-style capacitor model for diodes

Extends from BondLib.Interfaces.TwoPort (Partial model invoking two bondgraphic connectors).

Information

The Spice-style junction capacitance for DIODEs computes the depletion and diffusion capacitance value of a junction used in a DIODE. Different Spice dialects vary in the formulae they use for this purpose. Many Spice dialects actually don't use a formula for the junction capacitance at all, but rather compute the electric charge stored in the junction directly, which is conceptually cleaner. However, that approach is computationally cumbersome, as it leads to an awkward algebraic loop [1]. Thus, we chose to compute the junction capacitance, and use a (physically incorrect) approximate non-linear capacitor model. The numerical error should remain small, as the time constants associated with temperature variation are much larger than those associated with electrical phenomena.

This particular model uses the capacitance formulae advocated in [2].


Parameters:

 Level:   DIODE modeling level (default value = 1)
            Level=1: Non-geometric junction diode
            Level=2: Fowler-Nordheim diode
            Level=3: Geometric junction diode

 Tnom:    Reference temperature (default value = 300.15 K)

 IS:      Saturation current at reference temperature (default value = 1e-14 Amp)

 N:       Current mission coefficient (default value = 1)

 TT:      Transit time at reference temperature (default value = 0 sec)

 CJ:      Zero-bias bulk capacitance at reference temperature (default value = 0.5e-12 F)

 PB:      Built-in junction potential at reference temperature (default value = 0.8 Volt)

 MJ:      Bulk junction grading coefficient (default value = 0.33)

 EG:      Energy gap for temperature effect on saturation current at 0 K (default value = 1.11 Volt)

 XTI:     Temperature exponent of saturation current (default value = 3)

 FC:      Forward-bias depletion capacitance coefficient (default value = 0.5)

 BV:      Reverse breakdown voltage at reference temperature (default value = 0 Volt)

 IBV:     Reverse breakdown current (default value = 0 Amp)

 TCV:     Linear temperature coefficient of breakdown voltage (default value = 0 V/K)

 TTT1:    Linear temperature coefficient of transit time (default value = 0 s/K)

 TTT2:    Quadratic temperature coefficient of transit time (default value = 0 s/K2)

 ISW:     Saturation current of perimeter at reference temperature (default value = 0 Amp)

 CJSW:    Zero-bias perimeter capacitance at reference temperature (default value = 0.5e-12 F)

 PHP:     Built-in perimeter potential at reference temperature (default value = 0.8 Volt)

 MJSW:    Perimeter capacitance grading coefficient (default value = 0.33)

 TOX:     Thin oxide thickness (default value = 1e-7 m)

 GminDC:  Leakage conductance (default value = 1e-16 mho)

 Area:    Relative area occupied by the diode (default value = 1)

 PJ:      Relative perimeter width (default value = 1)

 EMin:    if x < EMin, the exp(x) function is linearized (default value = -100)

 EMax:    if x > EMax, the exp(x) function is linearized (default value = 40)

 L:       Diode length (default value = 0 m)

 W:       Diode width (default value = 0 m)

 M:       Diode multiplier (default value = 1)

 JS:      Saturation current density at reference temperature (default value = 1e-4 Amp/m2)

 CJ2:     Zero-bias bulk capacitance per meter square at reference temperature (default value = 1e-4 F/m2)

 JSW:     Saturation current density of perimeter at reference temperature (default value = 0 Amp/m2)

 CJSW2:   Zero-bias perimeter capacitance per meter at reference temperature (default value = 1e-9 F/m)

 LP:       Polysilicon length (default value = 0 m)

 WP:       Polysilicon width (default value = 0 m)

 XP:       Widening of polysilicon due to masking and etching (default value = 0 m)

 XOI:      Polysilicon thickness (default value = 0 m)

 LM:       Metal length (default value = 0 m)

 WM:       Metal width (default value = 0 m)

 XM:       Widening of metal due to masking and etching (default value = 0 m)

 XOM:      Metal thickness (default value = 0 m)

 JF:       Forward Fowler-Nordheim current coefficient (default value = 0 A/V2)

 JR:       Reverse Fowler-Nordheim current coefficient (default value = 0 A/V2)

 EF:       Forward Fowler-Nordheim critical electrical field (default value = 0 V/m)

 ER:       Reverse Fowler-Nordheim critical electrical field (default value = 0 V/m)


References:

  1. Cellier, F.E. (1991), Continuous System Modeling, Springer-Verlag, New York, pp. 224-225.
  2. Massobrio, G. and P. Antognetti (1993), Semiconductor Device Modeling with Spice, 2nd edition, McGraw Hill, New York, p.200.

Parameters

TypeNameDefaultDescription
IntegerLevel1DIODE modeling level (check documentation window for details)
Modelica.SIunits.TemperatureTnom300.15Reference temperature
Modelica.SIunits.CurrentIS1e-14Saturation current at reference temperature
RealN1Current emission coefficient
Modelica.SIunits.TimeTT0Transit time at reference temperature
Modelica.SIunits.CapacitanceCJ0.5e-12Zero-bias bulk capacitance at reference temperature
Modelica.SIunits.VoltagePB0.8Built-in junction potential at reference temperature
RealMJ0.33Bulk junction grading coefficient
Modelica.SIunits.VoltageEG1.11Energy gap for temperature effect on saturation current at 0 K
RealXTI3Saturation current temperature exponent
RealFC0.5Forward-bias depletion capacitance coefficient
Modelica.SIunits.VoltageBV0Reverse breakdown voltage at reference temperature
Modelica.SIunits.CurrentIBV0Reverse breakdown current
RealTCV0Temperature coefficient of breakdown voltage
RealTTT10Linear temperature coefficient of transit time
RealTTT20Quadratic temperature coefficient of transit time
Modelica.SIunits.CurrentISW0Saturation current of periphery at reference temperature
Modelica.SIunits.CapacitanceCJSW0.5e-12Zero-bias perimeter capacitance at reference temperature
Modelica.SIunits.VoltagePHP0.8Built-in perimeter potential at reference temperature
RealMJSW0.33Perimeter capacitance grading coefficient
Modelica.SIunits.LengthTOX1e-7Thin oxide thickness
Modelica.SIunits.ConductanceGminDC1e-16Leakage conductance
RealArea1Relative device area
RealPJ1Relative perimeter width
RealEMin-100if x < EMin, the exp(x) function is linearized
RealEMax40if x > EMax, the exp(x) function is linearized
Modelica.SIunits.LengthL0Diode length
Modelica.SIunits.LengthW0Diode width
IntegerM1Diode multiplier
Modelica.SIunits.CurrentDensityJS1e-4Saturation current density at reference temperature
RealCJ21e-4Zero-bias bulk capacitance per square meter at reference temperature
RealJSW0Saturation current density of periphery at reference temperature
RealCJSW21e-9Zero-bias perimeter capacitance per meter at reference temperature
Modelica.SIunits.LengthLP0Polysilicon length
Modelica.SIunits.LengthWP0Polysilicon width
Modelica.SIunits.LengthXP0Widening of polysilicon due to masking and etching
Modelica.SIunits.LengthXOI0Polysilicon thickness
Modelica.SIunits.LengthLM0Metal length
Modelica.SIunits.LengthWM0Metal width
Modelica.SIunits.LengthXM0Widening of metal due to masking and etching
Modelica.SIunits.LengthXOM0Metal thickness
RealJF0Forward FN current coefficient
RealJR0Reverse FN current coefficient
Modelica.SIunits.ElectricFieldStrengthEF0Forward critical electrical field
Modelica.SIunits.ElectricFieldStrengthER0Reverse critical electrical field

Connectors

TypeNameDefaultDescription
BondLib.Interfaces.BondConBondCon1 (from TwoPort)Left bond graph connector
BondLib.Interfaces.BondConBondCon2 (from TwoPort)Right bond graph connector
Modelica.Blocks.Interfaces.RealOutputidDiode current

Components

TypeNameDefaultDescription
Reale1 (from TwoPort)Bondgraphic primary effort
Realf1 (from TwoPort)Bondgraphic primary flow
Reale2 (from TwoPort)Bondgraphic secondary effort
Realf2 (from TwoPort)Bondgraphic secondary flow
BondLib.Junctions.J0p3J0p3_1
BondLib.Bonds.fBondB1
BondLib.Sensors.Devbi
BondLib.Sources.mSeVbi
BondLib.Bonds.fBondB3
BondLib.Junctions.J1p3J1p3_1
BondLib.Bonds.eBondB4
BondLib.Sensors.Dfid1
BondLib.Bonds.fBondB5
BondLib.Junctions.J0p3J0p3_2
BondLib.Bonds.fBondB6
BondLib.Bonds.fBondB7
BondLib.Bonds.fBondB8
BondLib.Sensors.DeTdev
BondLib.Junctions.J0p3J0p3_3
BondLib.Spice.Utilities.GjGj1
BondLib.Bonds.eBondB2
BondLib.Semiconductors.Utilities.mC2Cj1
BondLib.Spice.Utilities.nlCDnlC1
BondLib.Spice.Utilities.DjDDjD1
Bonds.eBondB9