* 2.6V to 5.5V Input Voltage Range
* Adjustable Output from 0.6V to VIN
* Guaranteed 3.0A Output Current
* Accurate Reference: 0.6V (+1%)
* Up to 95% Conversion Efficiency
* Low Quiescent Current
* Integrated Low RDS(ON) Upper and Lower MOSFET Switches: 80mΩ and 60mΩ
* Current Mode PWM Operation
* Fixed Frequency : 1.2MHz
* 100% Maximum Duty Cycle for Lowest Dropout
* Internal Soft-Start
* Over Voltage and Under Voltage Protection
* Over Temperature and Over Current Protection
* WDFN3x3-10L Package
* RoHS Compliant and Halogen Free

The uP1728S is a high efficiency synchronous-rectified
buck converter with internal power switches. Fixed 1.2MHz
PWM operation allows possible smallest output ripple and
external component size. With high conversion efficiency
and small package, the uP1728S is ideally suitable for
portable devices and USB/PCIE-based interface cards,
where PCB area is especially concerned.
With internal low R DS(ON) switches, the uP1728S is capable
of delivering 3.0A output current over a wide input voltage
range from 2.6V to 5.5V. The output voltage is adjustable
from 0.6V to V IN by a voltage divider.
Other features include internal soft-start, chip enable, over-
voltage, under-voltage, over-temperature and over-current
protections. The uP1728S is available in a space-saving
WDFN3x3-10L package.


* Battery-Powered Portable Devices
1. MP3 Players
2. Notebook Computers
3. Wireless and DSL Modems
4. Personal Information Appliances
5. IP Phones
6. Digital Cameras
* 802.11 WLAN Power Supplies
* FPGA/ASIC Power Supplies
* Dynamically Adjustable Power Supply for CDMA/WCDMA Power Amplifiers
* USB-Based xDSL Modems and Other Network Interface Cards
* Point-of-Load Regulation


uP1728S是一款高效率的同步整流降壓轉換器內部電源開關。固定的1.2MHz PWM操作允許可能最小輸出紋波和外部組件尺寸。具有高轉換效率和小封裝,uP1728S是非常適合便攜式設備和基於PCIE USB /接口卡,其中,PCB面積特別關注。