开关电源各种拓朴结构.ppt

Power Supply Topologies电源拓扑结构 The Most Popular Topologies最常见的拓扑结构 Buck降压 Boost升压 Buck-Boost降压-升压 Flyback反激 Forward正激 Two-Transistor Forward双晶体管正激 Push-Pull推挽 Half Bridge半桥 Full Bridge全桥 SEPIC C’uk The Basic Pulse-Width Modulated Waveform基本的脉冲宽度调制波形 These topologies all relate to switched-mode circuits.这些拓扑结构都与开关式电路有关。 Definition of the basic pulse-width modulated waveform is as follows:基本的脉冲宽度调制波形定义如下： Buck降压 Bucks the input down to a lower voltage.把输入降至一个较低的电压。 Perhaps the simplest of all.可能是最简单的电路。 The inductor/capacitor filter averages the rectangular wave from the switch.电感/电容滤波器滤平开关后的方波。 Output is always less than or equal to the input.输出总是小于或等于输入。 Input current is discontinuous (chopped).输入电流不连续 (斩波)。 Output current is smooth.输出电流平滑。 Boost升压 Boosts the input to a higher voltage.把输入升至一个较高的电压。 Like the buck, but inductor, switch and diode are rearranged.与降压一样，但重新安排了电感、开关和二极管。 Output is always greater than or equal to the input.输出总是比大于或等于输入。 (neglecting the forward voltage drop of the diode).(忽略二极管的正向压降)。 Input current is smooth.输入电流平滑。 Output current is discontinuous (chopped).输出电流不连续 (斩波)。 Buck-Boost 降压-升压 Another arrangement of the inductor, switch and diode.电感、开关和二极管的另一种安排方法。 Combines negative characteristics of both the buck and the boost.结合了降压和升压电路的缺点。 Input current is discontinuous (chopped).输入电流不连续 (斩波)。 Output current is also discontinuous (chopped).输出电流也不连续 (斩波)。 Output is always inverted from the input (note capacitor polarity), but can be of less or greater magnitude.输出总是与输入反向 (注意电容的极性)，但是幅度可以小于或大于输入。 The “flyback” converter is actually an isolated (transformer coupled) version of the buck-boost. “反激”变换器实际是降压-升压电路隔离（变压器耦合）形式。 Flyback 反激 Operates like the buck-boost, but the inductor has two windings and performs both as a transformer and inductor.如降压-升压电路一样工作，但是电感有两个绕组，而且同时作为变压器和电感。 Output can be either positive or negative, depending on the polarity of the winding and diode.输出可以为正或为负，由线圈和二极管的极性决定。 Output voltage