The MAX8640ZELT12+T is a tiny 500mA, 4MHz/2MHz synchronous step-down DC-DC converter in 6 pin μDFN package. This step-down converter is optimized for applications where small size, high efficiency and low output ripple are priorities. It utilizes a proprietary PWM control scheme that optimizes switching frequency for high efficiency with small external components and maintains low output ripple voltage at all loads. It switches up to 4MHz to allow a tiny 1μH inductor and 2.2μF output capacitor. Output current is up to 500mA while typical quiescent current is 28μA. Factory-preset output voltages from 0.8V to 2.5V eliminate external feedback components. Internal synchronous rectification greatly improves efficiency and replaces the external Schottky diode required in conventional step-down converters. Internal fast soft-start eliminates inrush current so as to reduce input capacitor requirements. It is used in microprocessor/DSP core power and I/O power.