In this paper, the concept of the adaptive CSDs is proposed for high frequency synchronous buck converters. The idea of the adaptive CSDs is to achieve optimal design of the switching loss reduction and the drive loss reduction for wide load range. It should be noted that the adaptive concept is suitable for both the continuous and discontinuous CSDs regardless the drive circuit topologies. Through investigating the CSD circuits, one simple method to achieve the adaptive drive current based on the adaptive voltages is proposed. The linear regulator can be used to achieve the function of the adaptive voltages and drive currents in a cost-effective manner. A 12V input, 1.3V output and 1MHz synchronous buck converter was built to verify the advantages of the proposed adaptive CSDs.