A package structure applied to power converters can include: a first die having a first power transistor and a first control and drive circuit; a second die having a second power transistor; a connection device configured to couple the first and second power transistors in series between a high-level pin and a low-level pin of a lead frame of the package structure; and where a common node of the first and second power transistors can be coupled to an output pin of the lead frame through a metal connection structure with a low interconnection resistance.