V

TT

LP2997

PV

IN

V

DDQ

V

REF

AV

IN

V

REF = 0.9V

V

SENSE

GND

+

+

+

AV

IN = 2.5V

V

TT= 0.9V

SD

SD

V

DDQ = 1.8V

C

IN

C

OUT

C

REF

LP2997

www.ti.com

SNVS295F – MAY 2004 – REVISED APRIL 2013

LP2997 DDR-II Termination Regulator

Check for Samples: LP2997

1

FEATURES

DESCRIPTION

The LP2997 linear regulator is designed to meet the

2

•

Source and Sink Current

JEDEC SSTL-18 specifications for termination of

•

Low Output Voltage Offset

DDR-II memory. The device contains a high-speed

•

No External Resistors Required

operational amplifier to provide excellent response to

load transients. The output stage prevents shoot

•

Linear Topology

through while delivering 500mA continuous current

•

Suspend to Ram (STR) Functionality

and transient peaks up to 900mA in the application as

•

Low External Component Count

required for DDR-II SDRAM termination. The LP2997

also incorporates a VSENSE pin to provide superior

•

Thermal Shutdown

load regulation and a VREF output as a reference for

•

Available in SOIC-8, SO PowerPAD-8 Packages

the chipset and DIMMs.

An additional feature found on the LP2997 is an

APPLICATIONS

active low shutdown (SD) pin that provides Suspend

•

DDR-II Termination Voltage

To RAM (STR) functionality. When SD is pulled low

•

SSTL-18 Termination

the

VTT output will tri-state providing a high

impedance output, but, VREF will remain active. A

power savings advantage can be obtained in this

mode through lower quiescent current.

Typical Application Circuit

Figure 1. Typical Application Circuit

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.