Winbond Electronics Corporation W971GG8JB-25

Overview

W971GG8JB-25 from Winbond is a 1G-bit DDR2 SDRAM organized as 16M × 8 banks × 8 bits, operating at DDR2-800 speed (5-5-5 timing), with 1.8 V ±0.1 V supply, SSTL_18 interface, and support for CAS latencies 3–7 in industrial-grade temperature range (0°C ≤ TCASE ≤ 85°C). It serves as main system memory in embedded controllers, network processors, and legacy industrial computing platforms requiring JEDEC-compliant synchronous DRAM.

For engineers reviewing the W971GG8JB-25 datasheet, W971GG8JB-25 pinout, W971GG8JB-25 application, or W971GG8JB-25 equivalent, key selection considerations include tRCD = 12.5 ns, ODT programmability via EMR, DLL-aligned DQS/DQ timing, and WBGA60 ball mapping for PCB layout and signal integrity validation.

Technical Context

This DDR2 SDRAM implements double-data-rate architecture with edge-aligned read data and center-aligned write data relative to differential DQS strobes. Its DLL synchronizes DQ and DQS transitions to CLK/CLK, enabling stable 400 MHz clock operation (tCK = 2.5 ns min at CL=5). Command decoding occurs on every positive CLK edge, with all control inputs (RAS, CAS, WE, CS) sampled synchronously.

Functional operation includes programmable additive latency (AL=0–2), auto-precharge for burst reads/writes, on-die termination (ODT) controlled by dedicated ODT pin and EMR(1), and OCD impedance calibration for output driver tuning. Refresh is supported via Auto Refresh (tREFI = 7.8 µs at ≤85°C) and Self Refresh modes, with high-temp refresh doubling required above 85°C.

Key Specifications

Pinout & Package

Package: WBGA60 (8 mm × 12.5 mm, 1.0 mm height), lead-free and RoHS compliant. Ball pitch: 0.8 mm. Thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H128M8CB-25E and IS42S16160F-25BLI, the W971GG8JB-25 offers native 8-bit width, full OCD/ODT configurability, and WBGA60 footprint optimized for compact industrial layouts - making it preferable where pin count, thermal profile, and signal tuning are constrained.

Availability

W971GG8JB-25 is available at Aetrix Electronics and suitable for industrial automation, legacy networking equipment, and medical imaging systems requiring stable component supply, long-lifecycle support, and JEDEC DDR2-800 compliance.

Supply support for W971GG8JB-25 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, flash, and logic ICs, with over 30 years of DRAM design heritage and global manufacturing scale.

The W971GG8JB series belongs to Winbond's industrial DDR2 SDRAM product line, engineered for reliability in extended-temperature embedded systems where drop-in compatibility with legacy JEDEC DDR2 controllers is mandatory.

FAQ

What is the maximum operating frequency supported by the W971GG8JB-25?

The W971GG8JB-25 is rated for DDR2-800 operation, meaning it supports a 400 MHz clock frequency with 800 MT/s data transfer rate. Its minimum clock period (tCK) is 2.5 ns at CAS Latency 5, and it guarantees full JEDEC AC/DC specifications across 0°C to 85°C case temperature. Operation beyond this speed grade is not validated and may result in timing violations or data corruption.

Does the W971GG8JB-25 support on-die termination (ODT), and how is it controlled?

Yes, the W971GG8JB-25 supports programmable on-die termination via both pin-strapped and register-controlled methods. The ODT pin enables termination resistance (75 Ω or 150 Ω) directly, while EMR(1) allows dynamic ODT configuration during operation. This dual-mode control lets designers optimize signal integrity for varying load conditions without modifying PCB layout, and is fully documented in the W971GG8JB-25 datasheet sections 8.2.4 and 10.4.

What is the purpose of the A10 pin in W971GG8JB-25 address mapping?

In the W971GG8JB-25, the A10 pin serves as the auto-precharge bit during READ and WRITE commands. When asserted HIGH during a burst access, it triggers automatic precharge of the accessed bank upon burst completion - eliminating the need for explicit PRECHARGE commands and improving memory controller efficiency. This behavior is defined in JEDEC DDR2 standard and confirmed in the W971GG8JB-25 functional description section 8.3.4 and 8.3.5.

Can the W971GG8JB-25 operate in self-refresh mode at elevated temperatures?

Yes, the W971GG8JB-25 supports self-refresh mode up to 85°C case temperature with IDD6 ≤ 10 mA. Above 85°C, JEDEC requires doubling the refresh rate (tREFI reduced from 7.8 µs to 3.9 µs), which is enabled by setting A7 = "1" in EMR(2). While the -25 speed grade is specified for 0°C–85°C operation, this high-temp self-refresh capability is implemented and verified per datasheet note 4, ensuring data retention in thermally stressed environments.

How does the W971GG8JB-25 handle differential data strobe (DQS) alignment during read and write operations?

The W971GG8JB-25 aligns DQS edge-to-edge with read data for precise capture timing, and centers DQS within write data windows to maximize setup/hold margins. This dual-alignment scheme - combined with DLL synchronization of DQ and DQS to CLK/CLK - ensures robust timing closure at 400 MHz. The behavior is fixed per JEDEC DDR2 specification and confirmed in W971GG8JB-25 datasheet sections 2 (Features) and 11.7–11.9 (timing waveforms).