A new way to extract the threshold voltage of MOSFET is presented. It combines the well known extraction method based on determining the maximum of the second derivative of I-D with respect to V-GS for V-DS approaching zero, with digital signal processing techniques to increase the signal/noise ratio. The derivatives are calculated on the Fourier transform space and a low-pass filter is used to smooth the function before taking the inverse transform. This procedure combines the advantage of being a standard method based on a physical property, with a noise immunity comparable to the most recent extraction methods, without requiring a costly computing effort. The results are compared with other methods using experimental data from 0.7 and 0.07 mum bulk CMOS technologies. (C) 2003 Elsevier Ltd. All rights reserved.