In this paper,a data-driven method for disturbance estimation and rejection is presented.The proposed approach is divided into two stages:an inner stabilization loop,to set the desired reference model,together with an outer loop for disturbance estimation and compensation.Inspired by the active disturbance rejection control framework,the exogenous and endogenous disturbances are lumped into a total disturbance signal.This signal is estimated using an on-line algorithm based on a data-driven predictor scheme,whose parameters are chosen to satisfy high robustness-performance criteria.The above process is presented as a novel enhancement to design a disturbance observer,which constitutes the main contribution of the paper.In addition,the control strategy is completely presented in discrete time,avoiding the use of discretization methods for its digital implementation.As a case study,the voltage control of a DC-DC synchronous buck converter affected by disturbances in the input voltage and the load is considered.Finally,experimental results that validate the proposed strategy and some comparisons with the classical disturbance observer-based control are presented.