8.4 A Fast-Transient 3-Fine-Level Buck-Boost Hybrid DC-DC Converter with Half-Voltage-Stress on All Switches and 98.2% Peak Efficiency

Shuangxing Zhao1,2; Chenchang Zhan2; Yan Lu1

10.1109/ISSCC49657.2024.10454536

2024-02-22

0193-6530

979-8-3503-0621-7

2024 IEEE International Solid-State Circuits Conference (ISSCC)

67

18-22 Feb. 2024

San Francisco, CA, USA

Buck-boost DC-DC converter plays an important role in battery-powered devices, as Li-ion battery outputs 4.2V to 2.8V while high-performance analog circuits require a relatively high supply of 3.3V. More importantly, an envelope supply modulator needs a buck-boost converter with wide and fast dynamics. A conventional buck-boost (CBB) converter has two main drawbacks: 1) all its four power switches need to withstand the highest voltage rating to cover the input/output voltage ranges, limiting the power conversion efficiency; 2) its inherent right-half-plane (RHP) zero limits the transient response speed. New topologies with flying capacitor $\left({\mathrm {C}}_{\mathrm {F}}\right)$ [1, 2] have been proposed to reduce the conduction loss by removing one switch in the main current path. However, during the mode transitions in [1, 2], the $\mathrm{C}_{\mathrm{F}}$ voltage would fluctuate, leading to significant charging or discharging currents that can create substantial current/voltage spikes and energy losses. Topologies in [3, 4] require only one mode for the entire operating range. Meanwhile, some topologies need LDMOS or stacked transistors for withstanding high-voltage stress, such as $\mathrm{V}_{\text{IN}}+\mathrm{V}_{\text{OUT}}$ in [1], $2 \mathrm{~V}_{\text{OUT}}$ in [3], or $2 \mathrm{~V}_{\text{IN}}$ in [4], which degrades the efficiency and increases fabrication cost. Still, these topologies exhibit slow transient response. To address this, [5, 6] propose buck-based topologies that eliminate the RHP zero. However, their efficiency is compromised by the additional switch in the main current path.

其他

EI

1.University of Macau, Macau, China
2.Southern University of Science and Technology, Shenzhen, China

Shuangxing Zhao,Chenchang Zhan,Yan Lu. 8.4 A Fast-Transient 3-Fine-Level Buck-Boost Hybrid DC-DC Converter with Half-Voltage-Stress on All Switches and 98.2% Peak Efficiency[C],2024.