Characterization and performance comparison of digital V2-type constant on-time control for buck converters
Characterization and performance comparison of digital V2-type constant on-time control for buck converters
复制标题
降压转换器数字 V2 型恒定导通时间控制的特性和性能比较
作者：
K. Cheng;Feng Yu;P. Mattavelli;F. Lee
本文基于所提出的小信号模型，描述了用于具有小 ESR 电容器的降压转换器的两种数字 V2 控制方案。由于模数转换器（ADC）的采样效应，即使使用电感电流感测反馈，数字V2控制系统的性能也不如模拟系统好。主要问题是，为了稳定系统并使系统具有良好的阻尼，需要大的外部斜坡或大的电流感应增益。然而，由于如此大的斜坡补偿，V2 控制架构的一些优点（包括快速瞬态和易于补偿）将消失。在本文中，提出了混合斜坡补偿概念来提高系统性能。给出了小信号建模分析和仿真验证。本文还给出了不同斜坡补偿下的负载瞬态实验结果。
This paper characterizes two digital V2 control schemes using for the buck converters with small-ESR capacitors based on the presented small-signal models. Due to the sampling effects of the analog-to-digital converters (ADCs), the digital V2 control system performances are not as good as the analog ones, even using the inductor current sensing feedback. The major issue is that in order to stabilize and to make the system well-damped, large external ramps or large current sensing gains are required. However, with such large ramp compensations, some benefits of the V2 control architecture, including the fast transients and the easily compensation, will be vanished. In this paper, a hybrid-ramp compensation concept is presented to improve the system performance. Both small-signal modeling analyses and simulation verifications are given. And the load transient experimental results with different ramp compensations are also shown in this paper.