An Extended Ramp Control Achieving Output Variation Reduction During Mode Transition for Hybrid Buck-Boost Converter
Journal
IEEE Transactions on Industry Applications
Start Page
1
End Page
14
ISSN
0093-9994
1939-9367
Date Issued
2026-05-05
Author(s)
Abstract
This paper presents a control integrated circuit (IC) with extended ramp control for a hybrid KY buck-boost converter in Lithium-ion battery-powered mobile devices. Hybrid topologies have been proposed to solve the problems of non-inverting buck-boost converters, including higher conduction loss and the right-half-plane (RHP) zero. For them, the KY buck-boost converter is a suitable solution with fewer added components and an established model. However, reducing output variation during mode transition remains critical for these hybrid converters. Compared to the pulse-width modulation (PWM) control, the proposed extended ramp control can achieve smaller output fluctuations during mode transitions and does not require an extra mode. This controller only requires a ramp, and the ramp signal is extended to decide the duty cycle in both buck mode and boost mode. The driver design and a pseudo-type-III compensator are also proposed in this work. The proposed compensator can greatly reduce the size of the passive devices without design constraints. Simulation results show that, compared to the non-inverting buck-boost converter with PWM control, output variation reduced from 36mV to 2mV during mode transition is achieved in this work. Additionally, when these two controllers are applied to the same KY buck-boost converter, only 2mV output variation is achieved with the proposed extended ramp control during mode transitions. The proposed KY buck-boost converter IC was fabricated with a 0.18-μm bipolar-CMOS-DMOS (BCD) process. Measurement results verified the proposed control, and the output fluctuation during mode transition is less than 20 mV without an extra mode. The peak efficiency of this work can achieve 94.1%.
Subjects
Buck-boost converter
hybrid buck-boost converter
KY buck-boost converter
lithium-ion battery management
mode transition
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Type
journal article