74SSTUB32868ZRHR

Specialty Logic Overview

The Texas Instruments 74SSTUB32868ZRHR is a 28-bit 1:2 configurable registered buffer designed for 1.7V to 1.9V VCC operation. It supports DDR2 registered DIMM applications, driving up to 18 SDRAM loads per device. The component features SSTL_18 data inputs and outputs optimized for unterminated lines, with LVCMOS control inputs. It includes address-parity testing on DIMM-independent data via an open-drain QERR output. Operating within the -40°C to 85°C industrial temperature range, it utilizes differential clock inputs (CLK and CLK) for data registration.

Specialty Logic Feature Summary

• Supports DDR2 registered DIMM applications with pinout optimized for PCB layout
• Includes parity checking function on DIMM-independent data inputs
• Features edge-controlled output circuitry to minimize switching noise in unterminated lines
• Provides low-power standby and active modes controlled by chip-select signals

Specialty Logic Applications

• DDR2 registered dual in-line memory modules (RDIMMs)

Specialty Logic Procurement Notes

Verify the specific ordering suffix ZRHR corresponds to the Tape and Reel packaging configuration. Confirm that the industrial temperature range (-40°C to 85°C) meets system requirements. Ensure compatibility with the 1.7V to 1.9V supply voltage specifications. Check for any recent product change notices or end-of-life notifications from Texas Instruments regarding this part number.

Specialty Logic Selection Notes

Select this component when designing DDR2 RDIMMs requiring a single device to drive up to 18 SDRAM loads. It is suitable for systems needing parity error detection on specific data bits. Consider the 176-TFBGA package constraints and the requirement for differential clock inputs. Evaluate the need for the configurable register A/B pinout options based on board routing complexity.

Specialty Logic Part Context

This device belongs to the Texas Instruments Widebus+ family of logic components. It is specifically engineered for high-speed memory interface applications where signal integrity and power efficiency are critical. The 74SSTUB32868 complements other memory controllers and buffers in DDR2 system architectures.

Specialty Logic Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

Specialty Logic FAQ

How does the device handle parity errors?

The device checks parity on DIMM-independent data inputs. If an error occurs, the open-drain QERR output is driven low and latched for a minimum of two clock cycles or until RESET is asserted.

What is the function of the C input?

The C input controls the pinout configuration between Register-A (C=0) and Register-B (C=1). It should be hard-wired during normal operation and not switched dynamically.