Abstract：In recent years,compared to conventional analog controlled voltage regulator module (VRM),digital controlled voltage regulator module is more popular because of its advantages. But there still exist several defects,like quantization effects,delay effects and so on. Usually these delays are inside the digital controller and it is hard to know the exact model. This paper proposes a small-signal model for digital controlled 12V ZVS self-driven voltage regulator module. Each part is modeled one by one in detail,finally making up a complete small signal model to guide the design. The model is also applicable for buck and multiphase interleaving buck converters. With this new model,frequency-domain characteristics are clearly explained. Moreover,a digital controller to achieve adaptive voltage positioning (AVP) function is designed. Simulations and experimental results are presented to prove the proposed small-signal model.
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2014, Vol. 29 
