The RT8020 is a dual high-efficiency Pulse-Width-Modulated (PWM) step-down DC-DC converter. It is capable of delivering 1A output current over a wide input voltage range from 2.5V to 5.5V, the RT8020 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources within the range such as cellular phones, PDAs and other hand-held devices.Two operational modes are available : PWM/Low-Dropout auto-switch and shutdown modes. 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 RT8020 enters Low-Dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper PMOS. The RT8020 enter shutdown 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 operation frequency of 1.5MHz. This along with small WDFN-12L 3x3 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.

Note :
Richtek Pb-free and Green products are :
► RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
► Suitable for use in SnPb or Pb-free soldering processes.

• +2.5V to +5.5V Input Range
• Adjustable Output From 0.6V to V_IN
• 1.2V, 1.3V, 1.8V, 2.5V and 3.3V Fixed/ Adjustable Output Voltage
• 1A Output Current
• 95% Efficiency
• No Schottky Diode Required
• 50μA Quiescent Current per Channel
• 1.5MHz Fixed-Frequency PWM Operation
• Small 12-Lead WDFN Package
• RoHS Compliant and 100% Lead (Pb)-Free

• Mobile Phones
• Personal Information Appliances
• Wireless and DSL Modems
• MP3 Players
• Portable Instruments

WDFN-12L 3x3

 Figure 1. Adjustable Voltage Regulator

V_OUTx = 1.2V, 1.3V, 1.8V, 2.5V or 3.3V

Figure 2. Fixed Voltage Regulator