NXP Semiconductors SSTUG32868ET/S,518

Overview

SSTUG32868ET/S from NXP Semiconductors is a 1.8 V, 28-bit, 1:2 configurable registered buffer with integrated parity checking, designed specifically for DDR2-1G RDIMM applications. It integrates dual JEDEC-standard register functionality into one TFBGA176 package, supports up to 450 MHz operation, delivers high-output-drive strength, and features two additional chip select inputs (DCS2/DCS3) and open-drain QERR error reporting for memory subsystems in high-density server DIMMs.

For engineers reviewing the SSTUG32868ET/S datasheet, SSTUG32868ET/S pinout, SSTUG32868ET/S application, or SSTUG32868ET/S equivalent, key selection criteria include its 28-bit 1:2 register architecture, SSTL_18-compatible D-inputs, differential CK/CK clock interface, 0°C to +85°C industrial temperature range, and support for parity-enabled RDIMM designs requiring stub-series terminated logic compliance and low-power standby modes.

Technical Context

The SSTUG32868ET/S implements a dual-register architecture controlled by the LVCMOS C input, selecting between Register A (C = 0) and Register B (C = 1) configurations with distinct data channel mappings-e.g., D1–D5/D7/D9–D12/D17–D28 vs. D1–D12/D17–D20/D22/D24–D28. Its parity engine accepts PAR_IN one clock cycle after data, generates QERR two cycles later, and latches errors for ≥2 clock cycles or until RESET assertion.

It uses differential CK/CK inputs with 600 mV minimum VID and 0.675–1.125 V common-mode range, supports SSTL_18 data inputs (VIH(AC) = Vref + 0.25 V), and employs edge-controlled CMOS outputs optimized for unterminated DIMM loads. The device enables low-power active mode via CSGEN and four DCS inputs, gating Qn/QERR outputs when all are HIGH, while RESET retains priority to force outputs LOW and disable receivers.

Key Specifications

Pinout & Package

Package: 176-ball thin fine-pitch ball grid array (TFBGA), 8 × 22 grid, 0.65 mm ball pitch, 6 mm × 15 mm body size, 0.7 mm height. Compatible with standard PCB assembly processes and provides thermal/mechanical reliability for memory module use.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR2 registered buffer applications.

Compared with IDT72V2851LPG and NB3N551DR2G, the SSTUG32868ET/S uniquely combines full 28-bit 1:2 registration, on-die even-parity checking with QERR, 450 MHz capability, and four-chip-select support-making it the only drop-in solution for high-reliability DDR2-1G RDIMMs requiring integrated error detection and industrial temperature operation.

Availability

SSTUG32868ET/S is available at Aetrix Electronics and suitable for server memory modules, enterprise storage controllers, and telecom baseband units requiring stable component supply, extended temperature performance (0°C to +85°C), and JEDEC-compliant DDR2 registered buffer functionality with integrated parity checking.

Supply support for SSTUG32868ET/S includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and communication markets.

The SSTUG32868ET/S belongs to NXP's SSTU family of DDR2 registered buffers, engineered specifically for high-density RDIMM applications demanding integrated parity, high-speed timing, and industrial-grade thermal reliability in server and infrastructure platforms.

FAQ

What is the operating temperature range of the SSTUG32868ET/S?

The SSTUG32868ET/S is rated for operation from 0 °C to +85 °C ambient temperature, making it suitable for industrial and enterprise server environments where commercial-grade (0°C to +70°C) parts may fail under thermal stress. This extended range is confirmed in Table 2 of the official NXP datasheet and applies specifically to the /S suffix variant.

How does the C input affect the pin configuration of the SSTUG32868ET/S?

The C input selects between Register A (C = LOW) and Register B (C = HIGH) configurations, altering which D-inputs feed which Q-output banks-for example, Register A uses D1–D5/D7/D9–D12/D17–D28, while Register B uses D1–D12/D17–D20/D22/D24–D28. The C pin must be hard-wired and not toggled during operation, as stated in Section 7.2 of the datasheet.

Does the SSTUG32868ET/S support parity checking, and how is it implemented?

Yes, the SSTUG32868ET/S implements even-parity checking across 22 DIMM-independent D-inputs. It accepts PAR_IN one clock cycle after the associated data, compares it internally, and asserts the open-drain QERR output (active LOW) two clock cycles later. The error remains latched for ≥2 clock cycles or until RESET is asserted, per Tables 4 and 5 in the datasheet.

What package type and ball count does the SSTUG32868ET/S use?

The SSTUG32868ET/S uses a 176-ball thin fine-pitch ball grid array (TFBGA) package with an 8 × 22 grid, 0.65 mm ball pitch, and 6 mm × 15 mm body dimensions (SOT932-1). This is explicitly defined in Table 1 of the NXP datasheet and confirmed in Figures 3–5 showing ball mapping for both Register A and Register B modes.

Can the SSTUG32868ET/S operate at DDR2-900 speed (450 MHz clock)?

Yes, the SSTUG32868ET/S supports a maximum clock frequency of 450 MHz, as specified in Table 9 (fclk = 450 MHz) and Table 10 (fclk(max) = 450 MHz). This enables full DDR2-900 operation (450 MT/s per pin) in registered DIMM applications, provided setup/hold timing (tsu = 0.5 ns, th = 0.4 ns) and load conditions are met.