Datasheet Texas Instruments 74SSTUB32868AZRHR

74SSTUB32868A
www.ti.com. SCAS846C – JULY 2007 – REVISED MARCH 2009 28-BIT TO 56-BIT REGISTERED BUFFER WITH ADDRESS-PARITY TEST FEATURES 1 Member of the Texas Instruments
Widebus+в„ў Family Pinout Optimizes DDR2 DIMM PCB Layout 1-to-2 Outputs Support Stacked DDR2 DIMMs One Device Per DIMM Required Chip-Select Inputs Gate the Data Outputs from
Changing State and Minimizes System Power
Consumption Output Edge-Control Circuitry Minimizes
Switching Noise in an Unterminated Line Supports SSTL_18 Data Inputs Differential Clock (CLK and CLK) Inputs
23 Supports LVCMOS Switching Levels on the
Chip-Select Gate-Enable, Control, and RESET
Inputs
Checks Parity on DIMM-Independent Data
Inputs
Supports industrial temperature range
(-40В°C to 85В°C)
RESET Input Disables Differential Input
Receivers, Resets All Registers, and Forces
All Outputs Low, Except QERR APPLICATIONS Heavily loaded DDR2 registered DIMM DESCRIPTION
This 28-bit 1:2 configurable registered buffer is designed for 1.7-V to 1.9-V VCC operation. One device per DIMM
is required to drive up to 18 stacked SDRAM loads or two devices per DIMM are required to drive up to 36
stacked SDRAM loads.
All inputs are SSTL_18, except the chip-select gate-enable (CSGEN), control (C), and reset (RESET) inputs,
which are LVCMOS. All outputs are edge-controlled circuits optimized for unterminated DIMM loads, and meet
SSTL_18 specifications, except the open-drain error (QERR) output.
The 74SSTUB32868A operates from a differential clock (CLK and CLK). Data are registered at the crossing of …