The FAN5358 is a step-down switching voltage regulator that delivers a fixed output from an input voltage supply of 2.7V to 5.5V. Using a proprietary architecture with synchronous rectification, the device is capable of delivering 500mA and maintaining a very high efficiency of over 80% at load currents as low as 1mA. The regulator operates at a nominal frequency of 2MHz, which reduces the value of the external components to as low as 2.2µH for the output inductor and 4.7µF for the output capacitor. At moderate and light loads, pulse frequency modulation is used to operate the device in power-save mode with a typical quiescent current of 25µA. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. In shutdown mode, the supply current drops below 1µA, reducing power consumption. FAN5358 is available in a 6-lead SC70 package.