This article presents the design of a two-stage 50 W portable charger architecture with universal ac input and 5 V/25 W, 9 V/45 W, 12 V/50 W output. A 98.5% efficient valley-switched boost converter operating at 0.5–2 MHz enables a 59% reduction in buffer capacitor volume compared to an example electrolytic capacitor while a stacked-bridge LLC converter with a Variable-Inverter-Rectifier-Transformer (VIRT) offers greater than 96% efficiency across the wide output voltage range. The design demonstrates the potential and trade-offs of a two-stage architecture at this operating power and illustrates the benefits of the utilized power stage topologies in achieving both small size and high efficiency over wide input- and output voltage ranges.

中文翻译：

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具有宽输出电压范围的两阶段通用输入充电器

本文介绍了具有通用交流输入和5 V / 25 W，9 V / 45 W，12 V / 50 W输出的两级50 W便携式充电器架构的设计。与示例电解电容器相比，工作于0.5–2 MHz的效率为98.5％的谷底开关升压转换器可将缓冲电容器的体积减少59％，而带有可变逆变器-整流器-变压器（VIRT）的叠桥LLC转换器可提供在较宽的输出电压范围内，效率均高于96％。该设计演示了在这种工作功率下两级架构的潜力和折衷方案，并说明了所利用的功率级拓扑在宽输入和输出电压范围内实现小尺寸和高效率的好处。