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, low-cost external surface-mount components. The inductor, at 3.3µH 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. The MAX767 is a monolithic BiCMOS IC available in 20-pin SSOP packages. For other fixed output voltages and package options, please consult the factory. Applications * Local 5V-to-3.3V DC-DC Conversion * Microprocessor Daughterboards * Power Supplies Up to 10A or More * >90% Efficiency * 700µA Quiescent Supply Current * 120µA Standby Supply Current * 4.5V-to-5.5V Input Range * Low-Cost Application Circuit * All N-Channel Switches * Small External Components * Tiny Shrink-Small-Outline Package (SSOP) * Predesigned Applications: * Standard 5V to 3.3V DC-DC Converters up to 10A * High-Accuracy Pentium P54C VR-Spec Supply * Fixed Output Voltages Available: * 3.3V (Standard) * 3.45V (High-Speed Pentium™) * 3.6V (PowerPC™)