10.4 A hybrid inductor-based flying-capacitor-assisted step-up/step-down DC-DC converter with 96.56% efficiency
10.4 A hybrid inductor-based flying-capacitor-assisted step-up/step-down DC-DC converter with 96.56% efficiency
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10.4%20A%20混合%20基于电感%20飞电容辅助%20升压/降压%20DC-DC%20转换器%20with%2096.56%%20效率
DOI：
10.1109/isscc.2017.7870322
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
G. Cho
中科院分区：
文献类型：
--
作者：
Yong;Se;Yeunhee Huh;Sang;Jun;Kiduk Kim;Sung;Ji;G. Cho
移动设备用户的数量每年都在增加。每个移动设备通常配备一个锂离子电池，其电压从最低2.7V到最高4.2V不等。因此，当电池电压随时间降低时，需要DC-DC变换器来提供低于或高于电池电压的稳压电源。简单的降压转换器不适合这种情况，因为升压转换是不可用的。相反，非反相降压升压转换器可以在整个电池电压范围内解决[1-4]。许多与锂离子电池运行的降压-升压转换器相关的研究将目标输出电压设定在3.4V左右[3,4]。由于锂离子电池在3.6V - 3.8V范围内具有较宽的平台，且平台以下储能较小，因此在大多数电池电压范围内，DC-DC变换器一般采用降压模式工作，如图10.4.1所示。尽管如此，升压转换也需要提取低于平台的能量，即使它是电池中的一小部分。因此，在DC-DC变换器中，当它在降压和升压模式下工作时，保持整个电池电压范围内的高效率是有效延长电池使用寿命的关键。然而，如果将图10.4.1左下的传统降压拓扑用于升压和降压目的，则通过电感器的主电流路径中总是有两个开关（S1和S3）导通。因此，开关的尺寸变大，以最小化传导损耗。由于开关尺寸越大，开关损耗也越大，因此这种结构的效率通常低于简单的降压（或升压）变换器[1]。在这方面，本文提出了一种名为飞电容降压（FCBB）转换器的拓扑结构，适合于这种应用，在整个电池电压范围内获得高效率的升压和降压操作。
The number of mobile device users increases every year. Each mobile device is usually equipped with a Li-ion battery having voltage that varies from a minimum of 2.7V to a maximum of 4.2V. Therefore, as the battery voltage decreases with time, a DC-DC converter is required for a regulated supply lower or higher than the battery voltage. A simple buck converter is not suited for this case, since step-up conversion is not available [1]. Instead, a non-inverting buck-boost converter can be a solution over the entire range of the battery voltage [1–4]. Many research studies related to buck-boost converters operated on Li-ion batteries set the target output voltage at around 3.4V [3,4]. Since Li-ion batteries have a wide plateau from 3.6V to 3.8V and a small energy storage below the plateau, DC-DC converters are generally operated on step-down mode at most of the battery voltage range, as shown in Fig. 10.4.1 top. Notwithstanding, step-up conversion is also required for extracting the energy below the plateau even if it is a small amount in the battery. Therefore, in DC-DC converters, it is critical to maintain high efficiency over the whole range of the battery voltage when it operates on both step-down and step-up modes to prolong the battery usage effectively. However, if the conventional buck-boost topology of Fig. 10.4.1 bottom-left is used for step-up and step-down purposes, there are always two switches (S1 and S3) conducting in the main current path through the inductor. Thus, the switches become large in size to minimize the conduction loss. As the switching loss also increases when the switch size is larger, the efficiency of this structure is usually lower than that of the simple buck (or boost) converter [1]. In this respect, this paper proposes a topology named a flying-capacitor buck-boost (FCBB) converter suitable for such an application by obtaining both step-up and step-down operations with high efficiency throughout the whole range of the battery voltage.