Efficiency Optimization of Integrated DC-DC Buck Converters
An analytic method to evaluate frequency dependent losses in on-chip DC-DC buck converters is presented in this paper. Microprocessors or chipsets exhibit wide dynamic range of load current varying from 50mA up to 1.5 A per phase at full operation. Peak efficiency is shown to occur when the load current related losses and the inherent losses of the DC-DC converter are equal. Efficiency optimization methods are described for light and heavy load scenarios. The primary design objective is to maintain the load at the peak of the efficiency curve.