Inversion charge modeling

A simple, implicit, relation for the inversion charge density in the channel of metal oxide semiconductor (MOS) transistors is presented. The relation is continuous and covers the whole operating range, from subthreshold to strong inversion. The derivative of the local inversion charge density with respect to the channel voltage is a simple expression in the charge density, leading to analytic integrals as required for obtaining the drain current and the capacitance coefficients.