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Subsections
Dxxxxxxx n+ n- mname {area} {args}
  .DIOde xxxxxxx n+ n- mname {area} 
        {args}
Junction diode.
N+ and n- are the positive and negative element nodes,
respectively.  Mname is the model name.  Area is the area
factor.  If the area factor is omitted, a value of 1.0 is assumed.
Args is a list of additional arguments.  The parameters
available are a superset of those available in SPICE.
A diode can also use a MOSFET model (type NMOS or PMOS) to
represent the equivalent of the source-bulk or drain-bulk diodes.
When the element is printed out, by a list or save
command, the the computed values of IS, RS, CJ, and
CJSW are printed as a comment if they were not explicitly
entered.
- Area = x
- Area factor.  (Default = 1.0) If optional
  parameters IS, RS, and CJO are not specified, the
  .model value is multiplied by area to get the actual
  value.
 
- Perim = x
- Perimeter factor.  (Default = 1.0) If
  optional parameter CJSW is not specified, the .model
  value is multiplied by perim to get the actual value.
 
- IC = x
- Initial condition.  The initial voltage to
  use in transient analysis, if the UIC option is specified.
  Default: don't use initial condition.  This is presently ignored,
  but accepted for compatibility.
 
- OFF
- Start iterating with this diode off, in DC analysis.
 
- IS = x
- Saturation current.  This overrides IS
  in the .model, and is not affected by area.  Default:
  use IS from .model * area.
 
- RS = x
- Ohmic (series) resistance.  This overrides
  RS in the .model, and is not affected by area.
  Default: use RS from .model * area.  This is
  presently ignored, but accepted for compatibility.
 
- CJ = x
- Zero-bias junction capacitance.  This
  overrides CJ in the .model, and is not affected by     area.  Default: use CJ from .model * area.
 
- CJSW = x
- Zero-bias sidewall capacitance.  This
  overrides CJSW in the .model, and is not affected by
  perim.  Default: use CJSW from .model *     perim.
 
- GParallel = x
- Parallel conductance.  This overrides
  GParallel in the .model, and is not affected by     area.  Default: use GParallel from .model *     area.
 
- IS = x
- Normalized saturation current. (Amperes).
  (Default = 1.0e-14) IS is multiplied by the area in the
  element statement to get the actual saturation current.  It may be
  overridden by specifying IS in the element statement.
 
- RS = x
- Normalized ohmic resistance. (Ohms) (Default
  = 0.)  RS is multiplied by the area in the element
  statement to get the actual ohmic resistance.  It may be overridden
  by specifying RS in the element statement.  RS is
  accepted, and silently ignored, for compatibility, but not
  implemented.
 
- N = x
- Emission coefficient. (Default = 1.0) In
  ECA-2 the default value was 2.
 
- TT = x
- Transit time. (Default = 0.)  The diffusion
  capacitance is given by:  where where is the diode
  conductance. is the diode
  conductance.
 
- VJ = x
- Junction potential.  (Default = 1.0) Used in
  computation of capacitance.  For compatibility with older versions
  of SPICE, PB is accepted as an alias for VJ.
 
- CJo = x
- Normalized zero-bias depletion capacitance.
  (Default = 0.)  CJo is multiplied by the area in the
  element statement to get the actual zero-bias capacitance.  It may
  be overridden by specifying CJ in the element statement.
 
- Mj = x
- Grading coefficient.  (Default = 0.5)
 
- PBSw = x
- Sidewall junction potential.  (Default =
  PB)
 
- CJSw = x
- Normalized zero-bias sidewall capacitance.
  (Default = 0.)  CJSw is multiplied by the perimeter in
  the element statement to get the actual zero-bias capacitance.  It
  may be overridden by specifying CJSW in the element statement.
 
- MJSw = x
- Sidewall grading coefficient.  (Default =
  0.33)
 
- EG = x
- Activation energy. (electron Volts) (Default
  = 1.11, silicon.)  For other types of diodes, use:
1.11 ev.  Silicon (default value)
 0.69 ev.  Schottky barrier
 0.67 ev.  Germanium
 1.43 ev.  GaAs
 2.26 ev.  GaP
 
 
- XTI = x
- Saturation current temperature exponent.
  (Default = 3.0) For Schottky barrier, use 2.0.
 
- KF = x
- Flicker noise coefficient.  (Default = 0.)
  SPICE parameter accepted but not implemented.
 
- AF = x
- Flicker noise exponent.  (Default = 1.0)
  SPICE parameter accepted but not implemented.
 
- FC = x
- Coefficient for forward bias depletion
  capacitance formula. (Default = 0.5)
 
- BV = x
- Reverse breakdown voltage.  (Default =
   .)  SPICE parameter accepted but not implemented. .)  SPICE parameter accepted but not implemented.
 
- IBV = x
- Current at breakdown voltage. (Default = 1
  ma.)  SPICE parameter accepted but not implemented.
 
- GParallel = x
- Parallel conductance. (Default = 0.)
 
- Vd
- Voltage.  The first node (anode) is assumed positive.
 
- Id
- Total current.  It flows into the first node (anode),
  out of the second (cathode).  I(Dxxxx) is the same as IJ(Dxxxx) +
  IC(Dxxxx).
 
- IJ
- Junction current.  The current through the junction.
  IJ(Dxxxx) is the same as I(Yj.Dxxxx).
 
- IC
- Capacitor current.  The current through the parallel
  capacitor.  IC(Dxxxx) is the same as I(Cj.Dxxxx).
 
- P
- Power.  P(Dxxxx) is the same as PJ(Dxxxx) + PC(Dxxxx).
 
- PD
- Power dissipated.  The power dissipated as heat.  It
  is always positive and does not include power sourced.  It should be
  the same as P because the diode is passive.
 
- PS
- Power sourced.  The power sourced by the part.  It is
  always positive and does not consider its own dissipation.  It
  should be 0 because the diode is passive.
 
- PJ
- Junction power.  PJ(Dxxxx) is the same as P(Yj.Dxxxx).
 
- PC
- Capacitor power.  PC(Dxxxx) is the same as
  P(Cj.Dxxxx).
 
- Capacitance
- Effective capacitance.  C(Dxxxx) is the same
  as Capacitance(Cj.Dxxxx).
 
- Req
- Effective resistance.  R(Dxxxx) is the same as
  R(Yj.Dxxxx).
 
- Z
- Impedance at a port.  The port impedance seen looking
  into the circuit across the branch.  It does not include the part
  itself.  In transient analysis, it shows the effective Z-domain
  impedance, which is a meaningless number if there are capacitors or
  inductors in the circuit.  (DC only)
 
- ZRAW
- Impedance at a port, raw.  This is the same as ``Z''
  except that it includes the part itself. (DC only)
 
- REgion
- Region code.  A numeric code that represents the
  region it is operating in.  +1 = forward, -1 = reversed, 0 =
  unknown, -2 = assumed off.
 
All parameters of the internal elements Yj and Cj are available.  To
access them, concatenate the labels for the internal element with the
diode, separated by a dot.  Yj.D6 is the admittance (Yj) element of
the diode D6.
In this release, there are no probes available in AC analysis except
for the internal elements.
The general element probes do not apply to diodes.
 
 
 
 
 
 
 
  
 Next: E: Voltage Controlled Voltage
 Up: Circuit description
 Previous: Trans-capacitor
     Contents 
Al Davis
2001-10-28