Partitioned-charge-based modeling of bipolar transistors for non-quasi-static circuit simulation

The concept of partitioned-charge-based (PC) modeling of bipolar transistors is developed and demonstrated, and shown to be fundamentally superior to conventional quasi-static charge-control modeling, the basis of the common (capacitance-based) Gummel-Poon (GP) equivalent circuit. SPICE transient simulations with PC and GP models are contrasted to show a first-order accounting for non-quasi-static (NQS) delay in the PC model which is not accounted for in the GP model. Additional model contrasts in the small-signal domain, compared with exact ac solutions, confirm the superiority of the PC model, the characterization of which is in fact no more tedious than that of the GP model.