LP2998MRX Datasheet, PDF (1/26 Pages) Texas Instruments – LP2998 DDR-I and DDR-II Termination Regulator

LP2998
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SNVS521I – DECEMBER 2007 – REVISED APRIL 2013
LP2998 DDR-I and DDR-II Termination Regulator
Check for Samples: LP2998
FEATURES
1
•2 Source and Sink Current
• Low Output Voltage Offset
• No External Resistors Required
• Linear Topology
• Suspend to Ram (STR) Functionality
• Low External Component Count
• Thermal Shutdown
• Available in SOIC-8, SO PowerPAD-8 Packages
APPLICATIONS
• DDR-I, DDR-II and DDR-III Termination Voltage
• SSTL-18 Termination
• SSTL-2 and SSTL-3 Termination
• HSTL Termination
DESCRIPTION
The LP2998 linear regulator is designed to meet
JEDEC SSTL-2 and JEDEC SSTL-18 specifications
for termination of DDR1-SDRAM and DDR-II
memory. The device contains a high-speed
operational amplifier to provide excellent response to
load transients. The output stage prevents shoot
through while delivering 1.5A continuous current as
required for DDR1-SDRAM termination, and 0.5A
continuous current as required for DDR-II termination.
The LP2998 also incorporates a V_SENSE pin to provide
superior load regulation and a V_REF output as a
reference for the chipset and DIMMs.
An additional feature found on the LP2998 is an
active low shutdown (SD) pin that provides Suspend
To RAM (STR) functionality. When SD is pulled low,
the V_TT output will tri-state providing a high
impedance output, while V_REF remains active. A
power savings advantage can be obtained in this
mode through lower quiescent current.
Typical Application Circuit
LP2998
SD
AV_IN = 2.5V
SD
AV_IN
V_REF
+
C_REF
V_REF = 0.9V
V_DDQ = 1.8V
V_DDQ
V_SENSE
+
C_IN
PV_IN
V_TT
GND
+
C_OUT
V_TT = 0.9V
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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