General Description
The RT5753 is a simple, easy-to-use, 3A synchronous
step-down DC-DC converter with an input supply voltage
range from 2.5V to 6V. The device builds in an accurate
0.6V reference voltage and integrates low RDS(ON) power
MOSFETs to achieve high efficiency in WDFN-8L 2x2 and
WDFN-8SL 2x2 packages.
The RT5753 adopts Advanced Constant On-Time (ACOT®)
control architecture to provide an ultrafast transient
response with few external components and to operate in
nearly constant switching frequency over the line, load,
and output voltage range. The RT5753A/C/E/F operates
in automatic PSM that maintains high efficiency during
light load operation. The RT5753B/D operates in Forced
PWM that helps to meet tight voltage regulation accuracy
requirements.
The RT5753 senses both FETs current for a robust
overcurrent protection. The device features cycle-by-cycle
current limit protection which prevents the device from
the catastrophic damage in output short circuit, over current
or inductor saturation. A built-in soft-start function prevents
inrush current during start-up. The device also includes
input undervoltage lockout, output undervoltage protection,
overvoltage protection (RT5753AL/BL/CL/DL/EL/FL) and
over-temperature protection to provide safe and smooth
operation in all operating conditions.

Features
 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/E/F)
 Advanced Constant On-Time (ACOT® ) Control
 Internal Soft-Start (1.5ms/750μs)
 Enable Control Input
 Power Good Indicator
 Both FETs Overcurrent Protection
 Negative Overcurrent Protection (RT5753B/D)
 Input Undervoltage Lockout Protection
 Output Undervoltage 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