The classical physics description long-channel undoped asymmetric independently driven double-gate MOSFETs channel potential has been modeled thus far by means of two types of equations consisting of either hyperbolic or trigonometric functions, as dictated by the applied bias conditions. Instead of such separate regional equations, we propose here the use of a single completely generic equation based on complex variables, which is valid for all values of front and back-gate bias. The unified nature of the proposed equation may be useful for future development of double-gate MOSFET modeling work because it provides a better basis for global physical insight. The solution of this equation is analyzed for several cases, including the all important fully symmetric one. (C) 2010 Elsevier Ltd. All rights reserved.