®
RT7241A
12A, 23V, 500kHz, ACOTTM Synchronous Buck Converter
with VTT LDO for Memory Power Supply
General Description
Features
DDR3/DDR3L/LPDDR3/DDR4 Complete Solution
The RT7241Aprovides a complete power supply forDDR3/
DDR3L/LPDDR3/DDR4 memory systems. It integrates an
Advanced Constant On-Time (ACOTTM) mode synchronous
Buck converter with a 1.5A sink/source tracking linear
regulator.
PWM Converter (VDDQ)
100μA Low Quiescent Supply Current at S3 Mode
ACOTTM Mode Performs Fast Transient Response
Support MLCC Output Capacitors
Integrated Low On-Resistance MOSFETs
17mΩ of High-Side MOSFET
The PWM converter provides low quiescent supply
current, high efficiency, excellent transient response, and
highDC output accuracy needed for stepping down high-
voltage batteries to generate low-voltage chipset RAM
supplies in notebook computers. The ACOTTM control
scheme handles wide input/output voltage ratios with ease
and provides a very fast response to load transients with
no external compensators.
4.5mΩ of Low-Side MOSFET
Adjustable from 0.6V to 1.5V Output Range for
1.5V (DDR3), 1.35V (DDR3L), 1.2V (LPDDR3) and 1.2V
(DDR4)
4.5V to 23V Battery Input Range
500kHz Switching Frequency
Resistor Adjustable Valley Current Limit
Over-/Under-Voltage Protection
The 1.5A sink/source VTT LDO maintains fast transient
response only requiring 10μF ceramic output capacitance.
The RT7241A supports all of the sleep state controls
placing VTT at high-Z in S3 and discharging VDDQ and
VTT in S4/S5.
Internal Voltage Ramp Soft-Start
Power Good Indicator
1.5A LDO (VTT)
Capable to Sink and Source up to 1.5A
LDO Input Available to Optimize Power Losses
Require Only 10μF Ceramic Output Capacitor
Integrated Divider Tracks 1/2 VDDQ for VTT
Accuracy 20mV for VTT
The RT7241A provides complete protection features
including OCP, OVP, UVP, and thermal shutdown. The
RT7241Ais available in the UQFN-18L 3x4 package.
Applications
DDR3/DDR3L/LPDDR3/DDR4 Memory Power Supplies
Support High-Z in S3 and Soft-Off in S4/S5
Tracking Mode Discharge Control
Thermal Capable Flip-chip (FC) Package for 12A
VDDQ Converter and 1.5A VTT LDO
RoHS Compliant and Halogen Free
Notebook computers
Simplified Application Circuit
Marking Information
BOOT
RT7241A
V
VIN
IN
C
B
C
C
L
IN
00= : Product Code
PHASE
V
DDQ
VDD
V
DD
R1
R2
YMDNN : Date Code
00=YM
C
OUT
VDD
FB
R
PGOOD
DNN
PGND
VDDQ
PGOOD
PGOOD
VLDOIN
S3
S5
S3
S5
VTT
VTTSNS
VTTGND
V
TT
C
VTT
GND
CS
R
CS
Copyright 2017 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS7241A-02 January 2017
www.richtek.com
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