Winbond Electronics Corporation W9751G8KB25I TR

Overview

W9751G8KB25I TR from Winbond is a 512 Mbit DDR2 SDRAM organized as 16M × 4 banks × 8 bits, operating at DDR2-800 speed (5-5-5 or 6-6-6 timing), with 1.8 V supply, industrial temperature range (–40°C to +95°C), and WBGA-60 package. It serves as main system memory in embedded controllers, network processors, and industrial HMIs requiring reliable high-bandwidth data buffering.

For engineers reviewing the W9751G8KB25I TR datasheet, W9751G8KB25I TR pinout, W9751G8KB25I TR application, or W9751G8KB25I TR equivalent, key selection criteria include CAS latency support (CL=3–7), on-die termination (ODT) programmability, OCD impedance calibration, differential clock interface (CLK/CLK), and industrial-grade thermal stability.

Technical Context

This DDR2 SDRAM implements a double-data-rate architecture synchronized to differential CLK/CLK inputs, with bi-directional DQS/DQS strobes edge-aligned on reads and center-aligned on writes. Its DLL aligns DQ and DQS transitions to clock edges, enabling stable 400 MHz operation (200 MHz clock, 400 MT/s per pin).

It supports programmable additive latency (AL=0–2), auto-precharge, burst lengths of 4 or 8, and multiple power management modes including precharged power down and self-refresh. ODT and OCD are controlled via extended mode registers (EMR1–EMR3), allowing dynamic signal integrity tuning without external components.

Key Specifications

Pinout & Package

W9751G8KB25I TR uses a 60-ball WBGA package (8 mm × 12.5 mm, RoHS-compliant, lead-free). Ball pitch is 0.8 mm; balls are arranged in an 8×8 grid with corner omissions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W9751G8KB25I TR, MT47H64M4HQ-25E IT:J offers higher density but demands board rework, while IS42S16400F-25BLI matches the WBGA-60 footprint and industrial temp but omits OCD calibration-making W9751G8KB25I TR the only option supporting both industrial operation and on-the-fly driver impedance tuning.

Availability

W9751G8KB25I TR is available at Aetrix Electronics and suitable for industrial HMIs, network processors, medical imaging controllers, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W9751G8KB25I TR 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

Winbond Electronics is a Taiwan-based semiconductor company specializing in specialty memory and microcontrollers, with over 30 years of DRAM design heritage and ISO/TS 16949-certified manufacturing.

The W9751G8KB series targets cost-sensitive, thermally demanding embedded systems requiring DDR2 compatibility, industrial qualification, and robust signal integrity features like OCD and ODT-without migrating to DDR3 complexity or cost.

FAQ

What is the maximum supported CAS latency for W9751G8KB25I TR?

W9751G8KB25I TR supports programmable CAS latency values of CL = 3, 4, 5, 6, and 7. At its rated DDR2-800 speed grade (tCK min = 2.5 ns), CL = 5 is the default and most commonly used setting, delivering optimal balance between access latency and timing margin. CL = 3 is supported only at reduced frequencies, while CL = 7 extends setup/hold windows for marginal layouts or high-noise environments. All values are configured via the Mode Register Set (MRS) command during initialization.

Does W9751G8KB25I TR support differential DQS operation?

Yes, W9751G8KB25I TR supports differential DQS operation using DQS and DQS pins. This mode is enabled by setting EMR(1)[A10] = 0 during extended mode register programming. When active, DQS functions as a true differential strobe aligned with data, improving noise immunity and timing margin. If single-ended mode is selected (EMR(1)[A10] = 1), DQS remains functional but DQS becomes NC, and ball A2 (NU/RDQS) is unused. The W9751G8KB25I TR datasheet confirms this behavior in Section 6 (Ball Description) and Section 8.2.2.1.

What is the purpose of the DM/RDQS pin on W9751G8KB25I TR?

The DM/RDQS pin on W9751G8KB25I TR serves dual functions: as Data Mask (DM) during write operations and as Read Data Strobe (RDQS) during reads-depending on EMR configuration. When EMR(1)[A11] = 0, it operates as DM: sampled on both DQS edges to mask corresponding DQ bits during writes. When EMR(1)[A11] = 1 and differential strobe mode is enabled, it outputs RDQS synchronized with read data. The pin's loading matches DQ/DQS for consistent signal integrity. This flexibility allows W9751G8KB25I TR to support both standard and enhanced DDR2 timing protocols.

How does OCD calibration work on W9751G8KB25I TR?

OCD calibration on W9751G8KB25I TR adjusts the output driver impedance of DQ and DQS pins to match the PCB's characteristic impedance (typically 50 Ω single-ended or 100 Ω differential). It is initiated after power-up and DLL enable via EMR(1) commands, using internal reference resistors. The process measures voltage ratios and programs trim codes into the OCD register, achieving ±10 % accuracy. Calibration must complete before normal operation begins-typically within 200 clock cycles-and can be repeated dynamically. This feature directly improves signal eye opening and reduces termination dependency on external resistors.

Is W9751G8KB25I TR pin-compatible with other Winbond DDR2 parts like W9751G8KB-25?

Yes, W9751G8KB25I TR is pin-compatible with W9751G8KB-25, sharing identical WBGA-60 package, ball map, and electrical interface. The sole difference is temperature qualification: W9751G8KB25I TR is specified for –40°C to +95°C (industrial grade), while W9751G8KB-25 is rated for 0°C to +85°C (commercial grade). Both use the same speed bin (DDR2-800, 5-5-5/6-6-6), command set, and initialization flow. No PCB or firmware changes are required when substituting W9751G8KB25I TR for W9751G8KB-25 in thermally demanding applications.