Next: , Previous: Transistors and Diodes, Up: Transistors and Diodes


8.5.1 Junction Diodes

General form:

       DXXXXXXX n+ n- mname <area=val> <m=val> <pj=val> <off> <ic=vd> <temp=val>
       +                    <dtemp=val>

Examples:

       DBRIDGE 2 10 DIODE1
       DCLMP 3 7 DMOD 3.0 IC=0.2

The pn junction (diode) implemented in NGSPICE expands the original spice's implementation. Perimetral effects and high injection level have been introduced into the original model and temperature dependence of some parameters has been added.

n+ and n- are the positive and negative nodes, respectively. mname is the model name, area is the area factor, pj is the perimeter factor, and off indicates an (optional)starting condition on the device for dc analysis. If the area factor is omitted, a value of 1.0 is assumed. The (optional) initial condition specification using ic is intended for use with the uic option on the .tran control line, when a transient analysis is desired starting from other than the quiescent operating point. You should supply the inital voltage across the diode there. The (optional) temp value is the temperature at which this device is to operate, and overrides the temperature specification on the .option control line. As always, instance temperature can be specified as an offset to the circuit temperature with the dtemp option.