RT7249

®

DS7249-02 March 2017

www.richtek.com

1

Copyright 2017 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

©

General Description

The RT7249 is a high efficiency, monolithic synchronous

step-downDC/DC converter with a power switch. The Buck

converter can deliver up to 3A output current from 4.5V to

18V input supply. The RT7249's current-mode architecture

and external compensation allow the transient response

to be optimized over a wide input range and loads. Cycle-

by-cycle current limit provides protections against shorted

output and soft-start eliminates input current surge during

start-up. The RT7249 also provides under-voltage protection

and thermal shutdown. PWM frequency is adjustable by

the ROSC pin and Power Switch current limit can also be

adjusted by the RLIM pin. The low current (<3

μA) in

shutdown mode provides output disconnection, enabling

easy power management in battery-powered systems. The

RT7249 is available in the WQFN-16L 4x4 package.

Simplified Application Circuit

Features











Buck Regulator



4.5V to 18V Input Voltage Range



3A Output Current



Internal N-Channel MOSFETs



Current Mode Control



Adjustable PWM Frequency



Adjustable Output from 0.8V to 15V



Adjustable Soft-Start Time



Stable with Ceramic Output Capacitors



Cycle-by-cycle Current Limit



Input Under-Voltage Lockout



Output Under-Voltage Protection



Thermal Shutdown











Power Switch



±±±±±15% Current-Limit Accuracy at 1.2A



Adjustable Current Limit : 75mA to 2580mA



Meet USB Current-Limiting Requirements



Reverse Input-Output Voltage Protection



Built-in Soft-Start



120m

Ω

Ω

Ω

Ω

Ω High-Side MOSFET



Operating Range : 2.5 V to 5.5 V











RoHS Compliant and Halogen Free

Marking Information

1A= : Product Code

YMDNN : Date Code

1A=YM

DNN

3A, 18V Synchronous Step-Down Converter with

Adjustable Current Limited Power Switch

RT7249

RLIM

FB

BOOT

LX

ROSC

PGND

EN_SW

Enable

EN

Enable

SW_OUT

SW_OUT

VIN

SW_IN

SW_IN

COMP