The initial frequency uncertainty tolerated by the Levenberg-Marquardt method applied to dynamic testing of A/D converters

This paper examines in some detail the convergence of the Levenberg-Marquardt method applied to A/D converter testing with sinusoidal stimulus. Firstly, we have determined the required initial guess accuracy in order to obtain the global convergence. Then, this result is used in order to develop a globally convergent modified Levenberg-Marquardt algorithm whatever the initial guess uncertainty. Simulation and experimental results are presented in order to show the effectiveness of this algorithm.