Abstract:In view of the required stability and rapidity of DC-DC buck converter, an improved design has been proposed of the constant frequency nonsingular terminal sliding mode controller. Compared with the average current technology, the controller can avoid the design of system compensator, thus solving the problems of unstable working frequency and slow response in traditional sliding mode control. By setting S-function as the switching surface and hyperbolic tangent function as the control law, the simulation and experimental results show that, with the changes of the input voltage and load current, the output voltage overshoot of DC-DC buck converter controlled by nonsingular terminal sliding mode technology is far less than that using average current technology, thus greatly improving the response speed.