Modeling of Voltage-Dependent Diffused Resistors

A voltage-dependent diffused resistor model has been developed using conventional voltage controlled current sources (VCCS’s) defined by a two-dimensional polynomial for simulations of mixed-signal circuits. The polynomial coefficients can be defined by a simple firstorder polynomial which can be a function of geometry and process variables to accurately reflect the manufacturing process. Alternatively, a conventional junction field effect transistor (JFET) model can be used to represent voltage dependence of the diffused resistor.