A diode requires a .model card to specify its characteristics. There are two types of diodes available. One is a conduction region-wise linear model that yields a computationally light weight representation of an idealized diode. It has three linear regions of conduction: on, off and reverse breakdown. Forward conduction and reverse breakdown can non-linear by specifying a current limit with Ilimit(revIlimit). tanh() is used to fit the slope of the forward conduction to the limit current. The parameters epsilon and revepsilon can be specified to smoothly switch between the off and conducting states. A quadratic function is fit between the off and on state such that the diode's IV curve is continuous in value and slope and the transition occurs over a voltage specified by the value of epsilon for the off to forward conduction and revepsilon for the transition between off and reverse breakdown.