Comparative study of linear and non-linear integrated control schemes applied to a Buck converter for mobile applications

Energy-efficient conversion of DC voltages is gaining more and more importance in low-power applications, especially in mobile and wireless systems. Several control techniques can be applied to achieve output regulation of a Buck DC-DC converter. In this paper a linear PID (proportional-integral-derivative) control loop, both in analog and digital domain, is derived and its performance is compared to a non-linear regulation loop based on the sliding-mode theory. A goal of this paper is to point out potential advantages and drawbacks of the different solutions. This exploration forms the starting point for the implementation of themost promising concepts in a 65nm CMOS technology.