The LP2998 linear regulator is designed to meet JEDEC SSTL-2 and JEDEC SSTL-18
specifications for termination of DDR-SDRAM and DDR2 memory. The device also supports DDR3 and DDR3L VTT bus termination with VDDQ min
of 1.35 V. The device contains a high-speed operational amplifier to provide excellent response to
load transients. The output stage prevents shoot through while delivering 1.5 A continuous current
and transient peaks up to 3 A in the application as required for DDR-SDRAM termination. The LP2998
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 LP2998 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.
