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10.4 A hybrid inductor-based flying-capacitor-assisted step-up/step-down DC-DC converter with 96.56% efficiency
- Source :
- ISSCC
- Publication Year :
- 2017
- Publisher :
- IEEE, 2017.
-
Abstract
- 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 (S 1 and S 3 ) 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.
- Subjects :
- 010302 applied physics
Forward converter
Engineering
Buck converter
business.industry
020208 electrical & electronic engineering
Ćuk converter
Buck–boost converter
Electrical engineering
Battery (vacuum tube)
02 engineering and technology
01 natural sciences
Undervoltage-lockout
0103 physical sciences
Boost converter
0202 electrical engineering, electronic engineering, information engineering
Electronic engineering
business
Voltage
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- 2017 IEEE International Solid-State Circuits Conference (ISSCC)
- Accession number :
- edsair.doi...........ca11ac7e9facd76d9696facbbf33e41b