T22.5 - Closed-Loop Stability Analysis of Digitally Current Mode Controlled Three-Level Buck Converter Using a Simplified Discrete-Time Modeling Framework

This digest introduces a discrete-time(DT) modeling framework and stability analysis for 3LBC that has been formally missing in the existing literature. The DT modeling is validated in the SIMPLIS environment for the large-signal as well as small-signal scenarios. The small-signal DT modeling in mixed-signal peak current-mode control(MSPCMC) is able to define stability boundaries for inductor and flying capacitor dynamics. The developed DT model is also shown to capture the non-linear sub-harmonic phenomenon which is consistent with experimental results of 12 V to 1 V 3LBC hardware prototype.