General Description

The RT5759A 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 output voltage

can be programmable from 0.6V to 1.725V with I2C

controlled 7-Bit VID.

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 RT5759A adopts Advanced Constant On-Time

(ACOT® ) control architecture that provides ultrafast

transient response and further reduces the externalcomponent

count. In steady states, the ACOT® operates

in nearly constant switching frequency over line, load and

output voltage ranges and makes the EMI filter design

easier. The RT5759A offers automatic PSM that maintains

high efficiency during light load operation. The RT5759A

can also operate in Forced-CCM through I2C setting that

helps meet tight voltage regulation accuracy requirements.

The device offers a variety of functions for more design

flexibility. The switching frequency, current limit level and

over-temperature threshold are selectable via I2C.

Independent enable control input pin and power good

indicator are also provided for easy sequence control.

Besides, the designer can also command the device to

be enabled or shutdown via the I2C interface.

The device offers independent enable control input pin and

power good indicator for easy 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. Full protection features are also

integrated in the device, including the cycle-by-cycle

current limit control, UVP, input UVLO and OTP.

The RT5759A is available in a thermally enhanced UQFN-

13L 3x3 (FC) package.

Features

 Dramatically Fast Transient Response

 Steady 1MHz ±20 Switching Frequency

 Advanced COT Control Loop

 Optimized for Ceramic Output Capacitors

 3V to 6.5V Input Voltage Range

 Integrated 12mΩ/8mΩ MOSFETs

 Internal Start-Up into Pre-Biased Outputs

 Power Good Indicator

 Enable Control

 Overcurrent and Over-Temperature Protections

 Undervoltage Protection with Hiccup Mode

 VID Control Range Via I2C Compatible Interface

0.6V to 1.725V step = 12.5mV

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