3MHz 4A High Efficiency Step-Down Converter with I²C Interface

The RT5701 is a Peak-Current Mode Pulse-Width-Modulated (PWM) step-down DC/DC converter with I²C control interface. Capable of delivering 4A continuing output current over a wide input voltage range from 2.5V to 5.5V, the RT5701 is ideally suited for Automotive Infotainment applications for low-voltage outputs to Micro controllers and ASICs in Navigation, Information Display, and Audio systems, Video systems and other battery operated systems requiring very low Shutdown current and Quiescent current consumption. Internal synchronous rectifier with low R_DS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky barrier diode is required in practical application. The RT5701 enters low-dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT5701 enters shut-down mode and consumes less than 5μA when the EN pin is pulled low. The switching ripple is easily smoothed-out by small package filtering elements due to a fixed operation frequency of 3MHz. This along with small TSSOP-14 (Exposed Pad) package provides small PCB area applications.

The RT5701 also includes Dynamic Voltage Scaling (DVS) for system low power applications.

The I²C interface let the RT5701 controllable flexibly to select V_OUT voltage level, peak current limit level, PWM control mode, and so on. Other features include soft-start, auto discharge, lower internal reference voltage, over-temperature, and over-current protection.