RT9173/A
Peak 3A Bus Termination Regulator
General Description
The RT9173/A regulator is designed to convert voltage
supplies ranging from 1.6V to 6V into a desired output
voltage which adjusted by two external voltage divider
resistors. The regulator is capable of sourcing or sinking
up to 3A of peak current while regulating an output voltage
to within 2% (DDR 1) and 3% (DDR 2) or less.
The RT9173/A, used in conjunction with series termination
resistors, provides an excellent voltage source for active
termination schemes of high speed transmission lines as
those seen in high speed memory buses and distributed
backplane designs. The voltage output of the regulator can
be used as a termination voltage for DDR SDRAM.
Current limits in both sourcing and sinking mode, plus onchip thermal shutdown make the circuit tolerant of the
output fault conditions.
Ordering Information
RT9173/A
Package Type
M5 : TO-263-5
L5 : TO-252-5
S : SOP-8
Operating Temperature Range
C : Commercial Standard
P : Pb Free with Commercial Standard
Features
Support Both DDR 1 (1.25VTT) and DDR 2
(0.9VTT) Requirements
SOP-8, TO-252-5 and TO-263-5 Packages
Capable of Sourcing and Sinking 3A Peak Current
Current-limiting Protection
Thermal Protection
Integrated Power MOSFETs
Generates Termination Voltages for SSTL-2
High Accuracy Output Voltage at Full-Load
Adjustable VOUT by External Resistors
Minimum External Components
Shutdown for Standby or Suspend Mode
Operation with High-impedance Output
RoHS Compliant and 100% Lead (Pb)-Free
Applications
DDR Memory Termination
Active Termination Buses
Supply Splitter
Pin Configurations
(TOP VIEW)
5
Note :
REFEN
3
VCNTL (TAB)
2
GND
1
3A Sink & Source
1.5A Sink & Source
VOUT
4
VIN
TO-263-5 (RT9173A)
RichTek Pb-free products are :
5
GND
1
−100%matte tin (Sn) plating.
VCNTL (TAB)
2
−Suitable for use in SnPb or Pb-free soldering processes.
REFEN
3
ments of IPC/JEDEC J-STD-020.
VOUT
4
−RoHS compliant and compatible with the current require-
VIN
TO-252-5 (RT9173A)
8
VCNTL
GND
2
7
VCNTL
REFEN
3
6
VCNTL
VOUT
4
5
VCNTL
VIN
SOP-8 (RT9173)
DS9173/A-15 March 2005
www.richtek.com
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