A new semi-empirical model for proton induced SEU is presented. For estimating the energy deposited by the protons in the sensitive volumes of the devices the model uses the measured spectra of surface barrier detectors (SBD) with the same thicknesses of the sensitive volume and at the same proton energies. Fitting the SBD spectra by exponential functions and the heavy ion induced cross sections by simple formulas results in simple expressions for the proton cross sections. The model predictions are in good agreement with the experimental results.