Extensive investigation of the drain-current low-frequency noise in n-channel MOSFETs issued from a 14-nm fully depleted silicon-on-insulator technology node has been carried out. The results demonstrate that the carrier number fluctuation (CNF) with correlated mobility fluctuations (CMFs) model accurately and continuously describes the 1/ f noise from weak to strong inversion, from linear to saturation, and for all the back-bias conditions. It is shown that using only two parameters, i.e., the effective flat-band voltage spectral density S Vfb,eff and CMF factor eff , the CNF/CMF noise model can predict the transistor 1/ f noise level of all channel dimensions and under any bias conditions. Thus, it can be easily used in SPICE noise modeling for circuit simulations.Index Terms-Low-frequency noise (LFN), UTBB fully depleted silicon-on-insulator (FDSOI) MOSFETs.