Design of buck DC-DC converters from the linear quadratic regulator approach

This paper presents the design guidelines of a control for step down (Buck) Direct Current to Direct Current (DC-DC) converter for hybrid and high power implementations. The DC-DC converter is analyzed and modeled with the state variables approach and based on the Sliding Mode Control (SMC) theory. A Continuous-Time Sigma Delta modulator performs the oversampled switching for the converter with benefits in the voltage ripple control. The proposed laws of control are implemented and verified though behavioral simulations in Mixed Signal mode verilogA descriptions. The results are shown with responses to different load values, showing control for every case. The proposed converter achieves a low output voltage ripple and a fast settling time.