High efficiency /high power density is one of the hottest research spots in power electronics technique. Due to simple structure and high conversion efficiency, the LLC resonant DC-DC converter has great utilization potential in many application areas. To improve the conversion efficiency and the power density further, synchronous rectifier is widely adopted at the secondary-side. Based on the existed synchronous rectified LLC resonant DC-DC converter reviewed in this paper, advantages and disadvantages are analyzed and compared in detail. A novel primary-side current sensing strategy and a new current driving method for voltage-doubler rectifier are presented. Finally, this paper proposes a family of novel single package structure for synchronous rectifier from the view point of power electronics integration to improve the performance further.