1. A method for performing a timing analysis on a network of cells, the network of cells comprising a first driver coupled to a first receiver, the method comprising: applying an input current signal to a model for the first receiver to generate a first model receiver signal; reading a first capacitance value from a cell entry for the first receiver in a characterized cell library; assigning the first capacitance value to a first non-linear capacitor in the model for the first receiver during generation of a first portion of the first model receiver signal; reading a second capacitance value from the cell entry for the first receiver in the characterized cell library; and switching, using a processor, the first non-linear capacitor in the model for the first receiver from the first capacitance value to the second capacitance value when the first model receiver signal reaches a first signal value.