General Description

The RT5750A/B is a simple, easy-to-use, 1A

synchronous step-down DC-DC converter with an input

supply voltage range from 2.5V to 6V. The device

build-in an accurate 0.6V reference voltage and

integrates low RDS(ON) power MOSFETs to achieve

high efficiency in a TSOT-23-5 and TSOT-23-6

package.

The RT5750A/B 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 RT5750A

operate in automatic PSM that maintain high efficiency

during light load operation. The RT5750B operate in

Forced PWM that help to meet tight voltage regulation

accuracy requirements.

The RT5750A/B senses both FETs current for a robust

over-current protection. The device features

cycle-by-cycle current limit protection and prevent 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, and

over-temperature protection to provide safe and

smooth operation in all operating conditions.

Features

 Input Voltage Range from 2.5V to 6V

 Integrated 120m and 80m FETs

 1A Output Current, up to 95 Efficiency

 100 Duty Cycle for Lowest Dropout

 1.5 Internal Reference Voltage

 1.5MHz Typical Switching Frequency

 Power Saving Mode for Light Loads (RT5750A)

 Low Quiescent Current: 25A (Typ.)

 Fast Advanced Constant On-Time (ACOT

Control

 Internal Soft Startup (0.6ms)

 Enable Control Input

 Power Good Indicator (TSOT-23-6)

 Both FETs Over-Current Protection

 Negative Over-Current Protection (RT5750B)

 Input Under-Voltage Lockout Protection

 Hiccup-Mode 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 Converter