Fairchild Semiconductor FAN4603 Synchronous Buck Regulators are fully integrated synchronous DC/DC buck converters that provide up to 600mA of output current over an input voltage ranging from 2.3V to 5.5V. Fairchild Semiconductor FAN4603 Synchronous Buck Regulators are offered as ultra-miniature "Solder and Play" solutions that require no external components and are each able to achieve a DC accuracy of ±2% PWM and an output ripple less than 12mV. With a total footprint of 4.0 x 2.5mm at a maximum height of 1.1mm, these can be used in small battery-powered devices and applications with distributed DC POL requirements.
At moderate and light loads, pulse frequency modulation is used to operate the FAN4603 in power-save mode with a typical quiescent current of 35µA. Even with such a low quiescent current, the Synchronous Buck Regulator exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed-frequency control. In shutdown mode, the supply current drops below 2µA, reducing power consumption.