Low‐complexity inductance estimation for switched‐mode power converters using peak‐current mode control

Abstract

This study describes a technique for automated and accurate inductance estimation in synchronous DC-DC buck and boost converters. The method of inductor value estimation is based on the dependence of the steady-state output voltage on the inductance value, in the case of a fixed inductor peak current. The measurement algorithm yields effective inductance value, and is aimed to be executed once during the start-up procedure under light load current condition. As the measurement is performed during the start-up sequence with low-load current, a dedicated current sensor with high accuracy can be employed, allowing to target high measurement accuracy in the range of ±5%. The presented technique is developed to enable the automated design of a digital controller for general purpose DC-DC converter but can be used in different applications such as analogue feedback-loop adjustment or improving the digital current estimator accuracy.

Pulse Bursting Phenomenon in Constant On-time Controlled Boost Converter

“…It is known that the overall output voltage ripple is composed of two terms, v c and v ESR . [11] Where v c is capacitor-based voltage ripple, which depends on the value of i L and I o , and v ESR is ESR-related voltage ripple, which is proportional to the value of R ESR . Generally speaking, the inductor current i L is usually larger than the load current I o for boost converter [12].…”

“…Generally speaking, the inductor current i L is usually larger than the load current I o for boost converter [12]. Thus, when S is turned on, the output capacitor provides energy to the load that makes v c decrease [12]; on the other hand, when S is turned off, v c increases due to i L > I o [10][11][12][13].…”