The ST1S15 is a high efficiency miniaturized step-down converter able to provide 500 mA output current from an input voltage from 2.3 V to 5.5 V. This converter is specifically designed for applications where high efficiency and small application area are the key factors. Thanks to 6 MHz switching frequency, the ST1S15 can use 470 nH nominal values for the inductor and 4.7 µF for the output capacitor providing, at the same time, very good performance in terms of load and line transients. A PFM mode can be selected for high efficiency under light load conditions or PWM mode for tight regulation and best dynamic performance. Short-circuit and thermal protection are also included.