General Description
The RT5753A/B/C/D 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 RT5753A/B/C/D 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
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 RT5753A/B/C/D senses both FETs current for a robust
over-current 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 under-voltage lockout, output under-voltage
protection, over-voltage protection (RT5753AL/BL/CL/DL)
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)
 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