General Description
The RT5758 is a high-performance, synchronous stepdown
DC-DC converter that can deliver up to 9A output
current from a 3V to 6.5V input supply. The device
integrates low RDS(ON) power MOSFETs, accurate 0.6V
reference and an integrated diode of bootstrap circuit to
offer a very compact solution.
The RT5758 adopts Advanced Constant On-Time (ACOTTM)
control architecture that provides ultrafast transient
response and further reduce the external-component
count. In steady states, the ACOTTM operates in nearly
constant switching frequency over line, load and output
voltage ranges and makes the EMI filter design easier.
The device offers Independent enable control input pin and
power good indicator for easily sequence control. To
control the inrush current during the startup, the device
provides a programmable soft-start up by an external
capacitor connected to the SS pin. Fully protection
features are also integrated in the device including the
cycle-by-cycle current limit control, UVP, input UVLO and
OTP.
The RT5758 is available in a thermally enhanced UQFN-
13L 3x3 (FC) package.

Features
 Dramatically Fast Transient Response
 Steady 1MHz ±20% Switching Frequency
 1.5% Reference Voltage
 Advanced COT Control Loop
 Auto PWM/Pulse Skipping Mode for High Light-
Load Efficiency
 Optimized for Ceramic Output Capacitors
 3V to 6.5V Input Voltage Range
 Integrated 12mΩ/8mΩ MOSFETs
 Pre-Biased Start Up
 Adjustable Soft-Start
 Power Good Indicator
 Enable Control
 Over-Current and Over-Temperature Protections
 Under-Voltage Protection with Hiccup Mode

Applications
 Mobile Phones and Handheld Devices
 STB, Cable Modem, and xDSL Platform
 WLAN ASIC Power / Storage (SSD and HDD)
 General Purpose for POL LV Buck Converter
 TV