An FPGA based digital control design for high-frequency DC-DC converters

Abstract

Advancement of processor technology has posed stringent requirements on the voltage regulating module (VRM) design. The control design has always been a problem that impedes the application of converter topologies in fast transient dc-dc conversion to meet the microprocessor demands. In this paper, we discuss the need for digital controllers for such applications. A simple design and implementation process of the compensators for the feedback loops is presented so as to attain the desired response of the system. A simple controller is obtained for a 4-phase interleaved converter which can be easily implemented on a simple digital platform. The discrete-time filter structure of such implementation is also presented and various implementation issues such as effect of sampling rate and effect of quantization of filter coefficients are discussed.