RT7249 Datasheet, PDF (1/17 Pages) Richtek Technology Corporation – Synchronous Step-Down Converter

®
RT7249
3A, 18V Synchronous Step-Down Converter with
Adjustable Current Limited Power Switch
General Description
The RT7249 is a high efficiency, monolithic synchronous
step-down DC/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 (<3μA) in
shutdown mode provides output disconnection, enabling
easy power management in battery-powered systems. The
RT7249 is available in the WQFN-16L 4x4 package.
Marking Information
1A=YM
DNN
1A= : Product Code
YMDNN : Date Code
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
 120mΩ High-Side MOSFET
 Operating Range : 2.5 V to 5.5 V
 RoHS Compliant and Halogen Free
Simplified Application Circuit
V_IN
SW_IN
Enable
Enable
RT7249
VIN
LX
BOOT
SW_IN
FB
EN_SW
EN ^SW_OUT
RLIM
COMP
ROSC
PGND
V_OUT
SW_OUT
Copyright ©2017 Richtek Technology Corporation. All rights reserved.
DS7249-02 March 2017
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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