H. Sakurai’s research while affiliated with Chuo University and other places

We propose the use of quadratic slope compensation in a current-mode DC-DC buck converter in place of the conventional linear slope compensation scheme. When the inductor-current detection circuit is constructed such that it has a transfer function that is inversely proportional to the input voltage, the slope value of the current feedback loop becomes insensitive to the converter's output voltage and the damping factor of the loop becomes constant. Therefore, stable operation with large frequency bandwidth is realized. Applying the quadratic slope compensation, a CMOS DC-DC buck converter was designed that had an output voltage range from 4.5V to 0.7V, an output current range up to 1A, and a switching frequency of 5MHz using a 0.6μm CMOS process.