The RT8059 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 2.8V to 5.5V. The RT8059 is ideally suited for portable electronic devices that are powered by 1-cell Li-ion battery or by other power sources within the range, such as cellular phones, PDAs and handy-terminals.
Internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical applications. The RT8059 automatically turns off the synchronous rectifier when the inductor current is low and enters discontinuous PWM mode. This can increase efficiency in light load condition.
The RT8059 enters low dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT8059 enters shutdown mode and consumes less than 0.1μA when the EN pin is pulled low.
The switching ripple can be easily smoothed out by small package filtering elements due to a fixed operation frequency of 1.5MHz. This along with small TSOT-23-5 package provides small PCB area application. Other features include soft-start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection.