The FAN5362 is a 500 mA or 750 mA, step−down, switching voltage regulator that delivers a fixed output voltage from an input voltage supply of 2.7 V to 5.5 V. Using a proprietary architecture with synchronous rectification, the FAN5362 is capable of delivering a peak efficiency of 96%, while maintaining efficiency over 90% with load currents as low as 1 mA. This regulator transitions seamlessly into and out of 100% duty cycle operation when the supply dips to or below the regulation setpoint and smoothly recovers full regulation without overshoot when the supply recovers. The regulator operates at a nominal fixed frequency of 3 MHz, which reduces the value of the external components to 1 H for the output inductor and 4.7 F for the output capacitor. The PWM modulator can be synchronized to an external frequency source. At moderate and light loads, pulse frequency modulation is used to operate the device in power−save mode with a typical quiescent current of 45 A. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed−frequency control, operating at 3 MHz. In shutdown mode, the supply current drops below 1 A, reducing power consumption. For applications that require minimum ripple or fixed frequency, PFM mode can be disabled using the MODE pin. The FAN5362 is available in 6−bump, 0.4 mm pitch, Wafer−Level Chip−Scale Package (WLCSP) and 6−Lead 2 x 2 mm Ultrathin Molded Leadless Package (UMLP)..