本文提出了高效的60W级两级AC-DC适配器的拓扑设计。 常规的60W级单级AC-DC转换器具有宽输入范围。 而且反激拓扑具有低效率的特点。 因此，常规的60W单级ACDC适配器具有低效率特性。 为了发展小型高效AC-DC转换器，提出了两级AC-DC转换器的结构。 两级AC-DC转换器增加了PFC级。 但是DC-DC级易于设计，因为输入电压固定了链路电容的电压。 此外，由于PFC级效应，输入滤波器的尺寸减小。 因此，两级AC-DC转换器具有高效率。 并且可以放入常规的单级AC-DC适配器盒中。 提出了升压PFC，反激，正向和LLC DC-DC转换器的设计程序和实验结果，以选择两级AC-DC转换器的合适拓扑。

Design on topologies for high efficiency 60W level two-stage AC-DC adapter is proposed in this paper. Conventional 60W level single-stage AC-DC converter has wide input range. And flyback topology has low efficiency characteristic. Therefore, conventional 60W single-stage ACDC adapter has low efficiency characteristic. In order to develop small and high efficiency AC-DC converter, propose two-stage AC-DC converter structure. Two-stage AC-DC converter is added PFC stage. But DC-DC stage easy to design Because input voltage fixed link capacitor voltage. Moreover, size of input-filter decrease due to PFC stage effect. Therefore, two-stage AC-DC converter has high efficiency. And it is possible to put in conventional single-stage AC-DC adapter case. Design procedures and experimental results for boost PFC, flyback, forward and LLC DC-DC converters are presented to select the suitable topologies of two-stage AC-DC converter.