The FAN53600/10 is a 3 MHz step-down switching voltage regulator, available in 600 mA or 1 A options, that delivers a fixed output from an input voltage supply of 2.3 V to 5.5 V. Using a proprietary architecture with synchronous rectification, the FAN53600/10 is capable of delivering a peak efficiency of 92%, while maintaining efficiency over 80% at load currents as low as 1 mA. The regulator operates at a nominal fixed frequency of 3 MHz, which reduces the value of the external components to as low as 1 µH for the output inductor and 4.7 µF for the output capacitor. In addition, the Pulse-Width Modulation (PWM) modulator can be synchronized to an external frequency source. At moderate and light loads, Pulse Frequency Modulation (PFM) is used to operate the device in Power-Save Mode with a typical quiescent current of 26 µA. 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 µA, reducing power consumption. For applications that require minimum ripple or fixed frequency, PFM Mode can be disabled using the MODE pin. The FAN53600/10 is available in 6-bump, 0.4 mm pitch, Wafer-Level Chip-Scale Package (WLCSP).