UR5596

The UTC UR5596 is a linear bus termination regulator and designed to meet JEDEC SSTL-2(Stub-Series Terminated Logic) specifications for termination of DDR-SDRAM. It also can be used in SSTL-3 or HSTL (High-Speed Transceiver Logic) scheme. The UR5596 contains a high-speed OP AMP to provide excellent response to the load transients, and can deliver 1.5A continuous current and transient peaks up to 3A in the application as required for DDR-SDRAM termination.

The UTC UR5596 also incorporates a VSENSE pin to provide superior load regulation and a VREF output as a reference for the chipset and DIMMs. Besides, an active low shutdown (SHDN) pin provides Suspend To RAM (STR) functionality. When SHDN is pulled low the VTT output will tri-state providing a high impedance output, but, VREF of UR5596 will remain active. A power savings advantage can be obtained in this mode through lower quiescent current. Regarding the output, VTT is capable of sinking and sourcing current while regulating the output voltage equal to VDDQ/2. The output stage has been designed to maintain excellent load regulation while preventing shoot through. The UTC UR5596 also incorporates two distinct power rails that separates the analog circuitry from the power output stage. This allows a split rail approach to be utilized to decrease internal power dissipation and permits UTC UR5596 to provide a termination solution for DDRII SDRAM.