ABSTRACT
In a DC–DC converter, both input and output voltages are DC. It uses a power semiconductor device as a switch to turn on and off the DC supply to the load. The switching action can be implemented by a BJT, a MOSFET, or an IGBT. A DC–DC converter with only one switch is often known as a DC chopper. A MOSFET is modeled as an intrinsic MOSFET with ohmic resistances in series with the drain, source, gate, and bulk (substrate). There is also a shunt resistance in parallel with the drain-source channel. NRD, NRS, NRG, and NRB are the relative resistivities of the drain, source, gate, and substrate in squares. PSpice Schematics does not incorporate a capacitance model involving the square root, which models the space charge layer variation for a step junction.
