®
RT5701
3MHz 4A High Efficiency Step-Down Converter with I
2
C
Interface
General Description
The RT5701 is a Peak-Current Mode Pulse-Width-
Modulated (PWM) step-down DC/DC converter with I
2
C
control interface. Capable of delivering 4A continuing output
current over a wide input voltage range from 2.5V to 5.5V,
the RT5701 is ideally suited for Automotive Infotainment
applications for low-voltage outputs to Micro controllers
and ASICs in Navigation, Information Display, and Audio
systems, Video systems and other battery operated
systems requiring very low Shutdown current and
Quiescent current consumption.
Internal synchronous rectifier with low R
DS(ON)
dramatically
reduces conduction loss at PWM mode. No external
Schottky barrier diode is required in practical application.
The RT5701 enters low-dropout mode when normal PWM
cannot provide regulated output voltage by continuously
turning on the upper P-MOSFET. The RT5701 enters shut-
down mode and consumes less than 5μA when the EN
pin is pulled low. The switching ripple is easily smoothed-
out by small package filtering elements due to a fixed
operation frequency of 3MHz. This along with small
TSSOP-14 (Exposed Pad) package provides small PCB
area applications.
The RT5701 also includes Dynamic Voltage Scaling (DVS)
for system low power applications.
The I
2
C interface let the RT5701 controllable flexibly to
select V
OUT
voltage level, peak current limit level, PWM
control mode, and so on. Other features include soft-start,
auto discharge, lower internal reference voltage, over-
temperature, and over-current protection.
Features
2.5V to 5.5V Input Range
Output Range from 0.3V to 5.5V
Bank 0 : 0.3V to 0.7V
�½
Bank 1 : 0.6V to 1.4V
�½
�½
�½
Bank 2 : 1.2V to 2.8V
Bank 3 : 2.4V to 5.5V
�½
The Default Value is 1.2V (VSEL = High) and 1.15V
(VSEL = Low)
4A Continuing Output Current
Support DVS in the Same Bank
�½
V
OUT
Adjusting Range (max, min) is Settable
High Efficiency
�½
83% at 5V
���
1.2V with 1.5A Load
3MHz Fixed-Frequency PWM Operation
�½
Auto-PSM/PWM or Force-PWM Selectable
Support Remote Ground Sensing for Accurate
Output Voltage
Dedicated Hardware Pin to Immediately Switch
Nominal Output Voltage Setting
Output Discharging when Turning Off
Over-Current Protection
OC Level Settable
Available in AEC-Q100 Grade 2 Qualified (105°C)
°
�½
Simplified Application Circuit
Input Power
RT5701
PVIN
LX
Load
AVDD
GNDR
Enable
I C Control
VOUT Select
2
Output
EN
SCL
SDA
VSEL
VOUT
GND
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5701-02 March 2018
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
