This article firstly, presents an analytical static model of single electron transistor (SET) based on the orthodox theory and enhanced to take into account the influence of temperature (thermionic current). Comparisons with the SIMON simulator and measurements show that our model is correct and accurate. Using this model, we analysed the performances of voltage controlled oscillators (VCO) based on two hybrid SET-MOSFET architectures. In particular we compared the VCO performances with ideal and realistic SETs for different CMOS technology nodes.