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In this study, a perturbation compensator is introduced in the sliding mode control (SMC) through a function of the prespecified sliding function, which is capable of estimating the lumped uncertainty and external disturbance with a known bandwidth. The approaches are designed to ensure a stable attraction and to attenuate the perturbation, which can be determined through the frequency domain analysis. Furthermore, an upper bound on the perturbation estimating error can be obtained based on the designed parameters, which depend on the bandwidth of the perturbation and the resonant frequency of the proposed estimator. Owing to the fact that the gain margin at zero frequency is infinity, the constant load disturbance can be estimated exactly. Combining the estimator with the sliding mode control method not only drastically reduces the gain of the discontinuous control term as compared with a conventional sliding mode control scheme but also achieves a chattering alleviated performance. In contrast to the SMC, the switching action is then performed in the bandwidth of the proposed compensator. For a disturbance-free system, this scheme not only establishes the sliding condition but also directly specifies the dynamic characteristics of the controlled system during the reaching stage, in which a discontinuous term is not needed. Experimental studies for the design of a turntable spindle servo system are conducted to illustrate its feasibility and effectiveness. [ABSTRACT FROM AUTHOR]