A simplified analytical approach within the framework of Landauer-Buttiker formalism has been employed to model the drain current in a ballistic n-channel metal oxide semiconductor field effect transistor (MOSFET) and the expression for the device threshold voltage has been obtained. To achieve ballistic operation the said MOSFET has been modeled considering low temperature (77 K) and intrinsic silicon channel for electronic motion of the charge carriers. The model incorporates quantum confinement effect, drain induced barrier lowering (DIBL) and short channel effects (SCE). Further, the effects due to surface scattering and back scattering are included in this model to obtain a near ballistic behavior. The current-voltage characteristics are compared with the available experimental results and are found to be in reasonable agreement.