3MHz 1A Step-Down Converter

The RT8048 is a high-efficiency Pulse-Width-Modulated (PWM) step-down DC/DC converter. Capable of delivering 1A output current over a wide input voltage range from 2.5V to 5.5V, the RT8048 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources such as cellular phones, PDAs and hand-held devices. Two operating modes are available including : PWM/Low Dropout auto switch and shut-down mode. The internal synchronous rectifier with low R_DS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application. The RT8048 enters Low-Dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT8048 enters shut-down mode and consumes less than 0.1μA when EN pin is pulled low. The switching ripple is easily smoothed-out by small package filtering elements due to a fixed operating frequency of 3MHz.