The RICHTEK IC is high quality!  Input Voltage Range from 2.5V to 6V
 Integrated 100mΩ and 70mΩ FETs
 100% Duty Cycle for Lowest Dropout
 Internal Reference Voltage with 1% Accuracy 1.2MHz Typical Switching Frequency
 Power Saving Mode for Light Loads (RT5753A/C)
 Advanced Constant On-Time (ACOT® ) Control
 Internal Soft-Start (1.5ms/750μs)
 Enable Control Input
 Power Good Indicator
 Both FETs Over-Current Protection
 Negative Over-Current Protection (RT5753B/D)
 Input Under-Voltage Lockout Protection
 Output Under-Voltage Protection
 Over-Temperature Protection
 RoHS Compliant and Halogen Free
Applications
 Mobile Phones and Handheld Devices
 STB, Cable Modem, and xDSL Platforms
 WLAN ASIC Power / Storage (SSD and HDD)
 General Purpose for POL LV Buck Converters