®
RT6243A/B
12A, 17V, High Efficiency Synchronous Step-Down Converter
General Description
The RT6243A/B is a high-performance, synchronous step-
down converter that can deliver up to 12A output current
with an input supply voltage range of 4.5V to 17V. The
device integrates low R
DS(ON)
power MOSFETs, accurate
0.6V reference and an integrated diode for bootstrap circuit
to offer a very compact solution.
The RT6243A/B adopts Advanced Constant On-Time
(ACOT
TM
) control architecture that provides ultrafast
transient response and further reduce the external-
component count. In steady states, the ACOT
TM
operates
in nearly constant switching frequency over line, load and
output voltage ranges and makes the EMI filter design
easier.
The device offers a variety of functions for more design
flexibility. The selectable switching frequency, current limit
level and PWM operation modes makes the RT6243A/B
easy-to-use over wide application range. Independent
enable control input pin and power good indicator are also
provided 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. Fully protection features are
also integrated in the device including the cycle-by-cycle
current limit, OVP, UVP, input UVLO and OTP.
The RT6243A/B is available in a thermally enhanced VQFN-
18L 3.5x3.5 (FC) package.
BOOT
1
2
3
4
5
6
7
Features
4.5V to 17V Input Voltage Range
Integrated 9.8mΩ/4.5mΩ MOSFETs
Ω
Ω
0.6V
±
1% Voltage Reference
Adjustable Output Voltage from 0.6V to 5.5V
Supports Ceramic Output Capacitor
ACOT
TM
Control for Fast Transient Response
Selectable Switching Frequency (400kHz/800kHz/
1200kHz)
Selectable Current Limit Level
Power Good Indicator
Programmable Soft-Start Time with a Default 1ms
Monotonic Start-Up into Pre-Biased Outputs
18-Lead VQFN (FC) Package
Applications
Server, Storage and Network Equipment
Telecom Infrastructure
Point of Load (POL) Power Modules
High Density DC-DC Converters
High End Digital TV
Pin Configuration
(TOP VIEW)
MODE
VCC
PGOOD
EN
SS
FB
18
17
16
15
14
13
12
11
10
9
8
AGND
VIN
PGND
PGND
PGND
Marking Information
RT6243AGQVF
1A= : Product Code
VIN
PGND
PGND
PGND
1A=YM
DNN
VQFN-18L 3.5x3.5 (FC)
RT6243BGQVF
19= : Product Code
19=YM
DNN
YMDNN : Date Code
Copyright
©
2019 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6243A/B-01 June 2019
SW
SW
YMDNN : Date Code
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
