Stability Prediction of Integrated-Circuit Based Constant ON-Time Controlled Buck Converters
Journal
IEEE Transactions on Power Electronics
Journal Volume
36
Journal Issue
6
Pages
6838-6849
Date Issued
2021
Author(s)
Abstract
The commonly used average model is not applicable to predict the stability performances of constant on-time (COT) controlled buck converters. It has been reported that the issues of stability can be addressed by using the control signal to output voltage transfer function of the converters, named GVC, for such class of converters. GVC can be mathematically derived using describing-function approach to include the effects of side-band harmonics of the pulsewidth modulation (PWM) modulator. This is essential for modeling the control behavior of the COT converter class. However, the actual GVC can deviate significantly from the derived ideal model. Therefore, a measured GVC transfer function is important for real-world stability predictions. GVC measurement, however, is often not feasible because the points of measurements are physically inaccessible due to integrated control circuit implementation. In this article, a realistic GVC extraction method is proposed for each of the four commonly used COT schemes. Based on the measured GVC, a procedure to predict the stability boundary is proposed and verified. ? 1986-2012 IEEE.
Subjects
DC-DC converters; Forecasting; Integrated circuits; Stability; Timing circuits; Transfer functions; Buck converters; Control circuits; Extraction method; Output voltages; Stability boundaries; Stability performance; Stability prediction; Time-controlled; Velocity control
Type
journal article