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