Maxim’s MAX8640Y/MAX8640Z step-down converters are optimized for applications where small size, high efficiency, and low output ripple are most important. The product utilizes a proprietary PWM control scheme that optimizes the switching frequency for high efficiency with the use of small external components and will maintain low output ripple voltage at all loads. The MAX8640Z switches at up to 4 MHz to allow a tiny 1 µH inductor and 2.2 µF output capacitor. The MAX8640Y switches at up to 2 MHz for higher efficiency while still allowing small 2.2 µH and 4.7 µF components. Output current is guaranteed up to 500 mA, while typical quiescent current is 28 µA. Factory-preset output voltages from 0.8 V to 2.5 V eliminate external feedback components.

The internal synchronous rectification greatly improves efficiency and replaces the external Schottky diode required in conventional step-down converters. The internal fast soft-start eliminates inrush current which reduces input capacitor requirements.