RT6254A Datasheet, PDF (1/18 Pages) Richtek Technology Corporation – ACOT Step-Down Converter

®
RT6254A/B
4A, 18V, 500kHz, ACOT^TM Step-Down Converter
General Description
The RT6254A/B is a high-efficiency, monolithic
synchronous step-down DC-DC converter that can deliver
up to 4A output current from a 4.5V to 18V input supply.
The RT6254A/B adopts ACOT architecture to allow the
transient response to be improved and keep in constant
frequency. Cycle-by-cycle current limit provides protection
against shorted outputs and soft-start eliminates input
current surge during start-up. Fault conditions also include
output under voltage protection and thermal shutdown.
Ordering Information
RT6254A/B
Package Type
J6F : TSOT-23-6 (FC)
J8F : TSOT-23-8 (FC)
Lead Plating System
G : Green (Halogen Free and Pb Free)
UVP Option
H : Hiccup
PSM/PWM
A : PSM/PWM
B : Force-PWM
Note :
Richtek products are :
 RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
 Suitable for use in SnPb or Pb-free soldering processes.
Features
 4.5V to 18V Input Voltage Range
 4A Output Current
 Constant-on-Time Mode to Enables Fast Transient
Response
 Low Output Ripple and Allows Ceramic Output
Capacitor
 500kHz Switching Frequency
 High Efficient Internal Power MOSFET Switch
Optimized for Lower Duty Cycle Applications
 Integrated 48mΩ/25mΩ MOSFETs
 Adjustable Output Voltage from 0.6V to 5V
 Internal Soft-Start (1.5ms typ.)
 Built-In UVP/OTP
 Power Good Indicator (90%)
 Input Under Voltage Lockout
 TSOT23-6 (FC) and TSOT23-8 (FC) Packages
Applications
 Set Top Box
 Portable TV
 Access Point Router
 DSL Modem
 LCD TV
Simplified Application Circuit
V_IN
C_IN
RT6254A/B
VIN
BOOT
Enable
EN
LX
R_PGOOD
PGOOD*
FB
AGND
GND
C_BOOT
L
R_T
R1 ^CFF
R2
C_OUT
V_OUT
* : PGOOD pin is for TSOT23-8 (FC) package.
Copyright ©2017 Richtek Technology Corporation. All rights reserved.
DS6254A/B-02 March 2017
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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