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.