降压/升压DC-DC转换器四开关控制方法

便携式电子应用设备常常要求它的系统电压，介于电池充分充电的电压和未充分放电的电压范围之间。比如，对于锂离子电池，当输入为2．8伏到4．2伏时，输出为3．3伏。达到这种要求最佳的解决方法就是高效率、同相的四开关拓扑结构的降压／升压DC-DC转换器，这种方法利用一种控制方案，它可以实现降压、降压／升压、升压三种模式自动并且平稳地转换。经HSPICE仿真，采用Hynix0．5um 5VCMOS工艺，在输入电压2．5～5．5V、输出电压3．3V、频率1MHz时，效率高达95％以上。是输出电压处于电池电压范围内的单节锂离子电池、多节碱性电池或NiMH电池应用的理想选择，解决了在便携式电子设备电源设计过程中所遇到的问题。

Four-Switch Control Method for Buck-Boost DC-DC Converter

A high efficiency control method with four switches for operating a non--inverting buck--boost DC/DC converter is adopted. The converter can regulate an output voltage higher, lower, or the same as the input voltage. This solution uses a control scheme which provides automatic and smooth transition through boost, buck--boost and buck modes. The topology incorporated in the IC provides a continuous transfer function through all operating modes. HSPICE simulations are done on the regulator with Hynix 0. 5 um 5 V CMOS process. When the supply is 2. 5 V to 5. 5 V, the output 3. 3 V and the frequency 1 MHz, the efficiency is up to 95%. The switching regulator makes the product ideal for single lithiumion, multicell alkaline or NiMH applications where the output Voltage is within the battery voltage range and solves a problem encountered often in designing power supplies for portable electronics.