Insights on the Dynamic Performance of Nonminimum-Phase Boost Converters Exploiting Inductor-Current-Feedback RHPZ Mitigation

Inductor current feedback (ICF) has been recently proposed to mitigate the adverse effect of the right-half-plane zero (RHPZ) in non-minimum phase (NMP) boost converters. Basically, ICF is used to move the RHPZ into the left-half-plane, leading to increased closed-loop stability. This paper systematically investigates the impact of the ICF mitigation technique on the dynamic performance of the converter. It is shown that both line and load transient responses are still limited by the RHPZ despite the exploitation of ICF. Compared to a boost converter equipped with a properly designed proportional-integral-derivative (PID) controller, the use of ICF leads to a load transient response with similar peak overshoots/undershoots but slower settling time, whereas the line transient response shows a significant reduction in the peak overshoots/undershoots. The theoretical analysis and the proposed design guidelines are verified with SIMetrix/SIMPLIS and MATLAB/Simulink simulations. Experimental results from a prototype boost converter designed for 2.3–4.5 V to 5 V voltage conversion, 800 mA load current capability, provide further validation.