The disclosed embodiments include systems and methods of building an agnostic model of a physically-based semiconductor device. The embodiments may include implementing, in the agnostic model, an arbitrary voltage source in series between a node voltage and a zero value voltage source, implementing, in the agnostic model, a reference capacitor in series between the node voltage and a dummy voltage source, implementing, in the agnostic model, an arbitrary current source between a first node and a second node. The arbitrary current source may include the dummy voltage source divided by the reference capacitor, and the arbitrary current source may model the change in the any property, such as charge, over time within the semiconductor device.