Implementation of digital control for buck converter by means a single DSP

This paper describes a step-by-step DSP based digital control design and implementation of a high frequency dc-dc converter. Starting with a dc-dc buck converter and a given set of performance specification, it discusses different control blocks, different control design approaches and highlights the significant differences in designing control in the digital domain compared to the analog approach. Two approaches to the digital control design are illustrated namely, the design by emulation and the direct digital design. These are first shown in MATLAB and then verified by experimental results. In this process the effects of sampling delay and the computation delay are also analyzed in MATLAB and then verified experimentally. Finally the assembly code listings implementing the designed controllers are provided in order to aid the users quickly validate these controllers using a similar DSP controlled dc-dc converter set up.