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