LP2997 DDR-II Termination Regulator
June 2004
LP2997 DDR-II Termination Regulator
General Description
The LP2997 linea...
LP2997 DDR-II Termination
Regulator
June 2004
LP2997 DDR-II Termination
Regulator
General Description
The LP2997 linear
regulator is designed to meet the JEDEC SSTL-18 specifications for termination of 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 500mA continuous current and transient peaks up to 900mA in the application as required for DDR-II SDRAM termination. The LP2997 also incorporates a VSENSE pin to provide superior load regulation and a VREF output as a reference for the chipset and DIMMs. An additional feature found on the LP2997 is an active low shutdown (SD) pin that provides Suspend To RAM (STR) functionality. When SD is pulled low 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.
Features
n n n n n n n n 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 SO-8, PSOP-8 packages
Applications
n DDR-II Termination Voltage n SSTL-18 Termination
Typical Application Circuit
20109418
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LP2997
Connection Diagrams
20109403
PSOP-8 Layout
20109404
SO-8 Layout
Pin Description
SO-8 Pin or PSOP-8 Pin ...