The MAX8640Y/MAX8640Z step-down converters are optimized for applications where small size, high efficiency, and low output ripple are priorities. They utilize a proprietary PWM control scheme that optimizes the switching frequency for high efficiency with small external components and maintains low output ripple voltage at all loads. The MAX8640Z switches at up to 4MHz to allow a tiny 1H inductor and 2.2F output capacitor. The MAX8640Y switches at up to 2MHz for higher efficiency while still allowing small 2.2H and 4.7F components. Output current is guaranteed up to 500mA, while typical quiescent current is 28A. 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.