The MAX767 is a high-efficiency, synchronous buck controller IC dedicated to converting a fixed 5V supply into a tightly regulated 3.3V output. Two key features set this device apart from similar, low-voltage step-down switching regulators: high operating frequency and all N-channel construction in the application circuit. The 300kHz operating frequency results in very small, lowcost external surface-mount components. The inductor, at 3.3H for 5A, is physically at least five times smaller than inductors found in competing solutions. All N-channel construction and synchronous rectification result in reduced cost and highest efficiency. Efficiency exceeds 90% over a wide range of loading, eliminating the need for heatsinking. Output capacitance requirements are low, reducing board space and cost.