Winbond Electronics Corporation W972GG8JB-25 TR

Overview

W972GG8JB-25 TR from Winbond Electronics is a 2G-bit DDR2 SDRAM organized as 32M × 8 banks × 8 bits, operating at DDR2-800 speed (5-5-5 or 6-6-6 timing), with 1.8 V supply, SSTL_18 interface, and on-die termination (ODT) for high-speed memory subsystems in industrial computing and embedded controllers.

For engineers reviewing the W972GG8JB-25 TR datasheet, W972GG8JB-25 TR pinout, W972GG8JB-25 TR application, or W972GG8JB-25 TR equivalent, key selection criteria include CAS latency support (CL=3–7), burst length (4/8), OCD impedance calibration, differential clock input compatibility, and WBGA-60 package thermal and layout constraints.

Technical Context

This DDR2 SDRAM implements a double-data-rate architecture synchronized to differential CLK/CLK inputs, with DLL-aligned DQ/DQS timing, posted CAS with programmable additive latency (AL=0–2), and source-synchronous read/write strobing using edge-aligned DQS (read) and center-aligned DQS (write). It supports both single-ended and differential DQS modes via EMR(1) configuration.

Functional operation includes auto-precharge, self-refresh, active/precharged power-down modes, ODT control per bank, and OCD impedance adjustment across VDDQ pins. The device uses a 4-bank × 8-bank internal organization with 32,768 × 1,024 × 8 cell array mapping, supporting tRCD/tRP/tRC minima of 12.5 ns at DDR2-800 speed grade.

Key Specifications

Pinout & Package

Package: WBGA-60 (11 mm × 11.5 mm, 1.0 mm height), lead-free and RoHS-compliant, with ball pitch of 0.8 mm and VDD/VSSQ/VDDL/VSSDL isolation for noise suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H64M8CB-25E:H and IS42S16400F-25BLI, the W972GG8JB-25 TR offers finer OCD tuning and tighter VDDQ tolerance (±0.1 V), making it preferable for thermally constrained industrial designs where signal margin is prioritized over JEDEC certification or component count reduction.

Availability

W972GG8JB-25 TR is available at Aetrix Electronics and suitable for industrial PLC memory buffers, medical imaging frame stores, network router packet buffers, and automotive ADAS video preprocessors requiring stable component supply across extended product lifecycles.

Supply support for W972GG8JB-25 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 manufacturer specializing in specialty memory solutions including NOR/NAND Flash, SRAM, and DDR SDRAM for industrial, automotive, and communications markets.

The W972GG8JB series belongs to Winbond's industrial-grade DDR2 SDRAM product line, designed specifically for applications demanding robust thermal performance, long-term supply stability, and advanced signal integrity features like OCD and programmable ODT.

FAQ

What is the maximum supported CAS latency for W972GG8JB-25 TR?

The W972GG8JB-25 TR supports programmable CAS latency values of CL=3, 4, 5, 6, and 7. At its rated DDR2-800 speed grade, CL=5 is the most commonly used setting, delivering optimal balance between access latency and timing margin. CL=3 is usable only at reduced frequencies or with aggressive board-level tuning, while CL=7 extends timing slack for marginal signal integrity conditions. All settings are configured via the Mode Register Set (MRS) command during initialization.

Does W972GG8JB-25 TR support differential DQS operation?

Yes, the W972GG8JB-25 TR supports differential DQS operation using DQS/DQS pins. This mode is enabled by setting EMR(1)[A10] = 0 during initialization. When active, DQS functions as a true differential strobe aligned with read data (edge-aligned) and write data (center-aligned), improving jitter immunity and timing margin. Single-ended DQS mode remains available via EMR(1)[A10] = 1, but differential mode is recommended for layouts exceeding 8-inch trace lengths or operating above 333 MHz.

What is the purpose of the VDDL and VSSDL pins on W972GG8JB-25 TR?

VDDL and VSSDL are dedicated power and ground supplies for the internal DLL (Delay-Locked Loop) circuitry in the W972GG8JB-25 TR. Isolating the DLL domain minimizes noise coupling from core logic and I/O switching, ensuring stable clock alignment between DQ and DQS signals. VDDL must be supplied at 1.8 V ± 0.1 V and decoupled independently from VDD/VDDQ; VSSDL must be routed separately to avoid shared impedance paths that could degrade DLL jitter performance.

Can W972GG8JB-25 TR operate without external termination resistors?

Yes, the W972GG8JB-25 TR can operate without external termination resistors due to its integrated On-Die Termination (ODT) feature. When ODT is asserted HIGH, internal 75 Ω or 150 Ω resistors are enabled on DQ and DQS lines, eliminating the need for discrete parallel terminations. This simplifies PCB layout, reduces BOM cost, and improves signal integrity in point-to-point configurations-provided the memory controller supports ODT control signaling and timing budget accounts for ODT turn-on delay (tODTon).

What initialization sequence is required before normal operation of W972GG8JB-25 TR?

The W972GG8JB-25 TR requires a strict 13-step power-up and initialization sequence: (1) Apply stable VDD/VDDQ/VDDL within ramp limits; (2) Stabilize CLK/CLK for ≥200 µs; (3) Assert CKE HIGH; (4) Issue PRECHARGE ALL; (5–6) Program EMR(2) and EMR(3); (7) Enable DLL; (8) Reset DLL; (9) PRECHARGE ALL again; (10) Two AUTO REFRESH commands; (11) MRS to set CL/BL; (12) OCD calibration; (13) Final MRS. Skipping any step may result in undefined behavior or failed DLL lock.