I. Introduction
With the development of digital devices, such as microprocessors, digital signal processors (DSPs), field programmable gate arrays (FPGAs), and so on, the digital control of switching dc–dc converters has become more and more popular and feasible [1]–[4]. The digital control of switching dc–dc converters has advantages of lower power consumption, ability to interface with digital systems, immunity to component variations, flexibility to implement sophisticated control schemes, and potentially faster design process [5]–[7].