Winbond Electronics Corporation W971GG8SB-25

Overview

W971GG8SB-25 from Winbond is a 1G-bit DDR2 SDRAM organized as 16M × 8 banks × 8 bits, supporting DDR2-800 (5-5-5 or 6-6-6) operation at 400 MHz clock frequency with 1.8 V supply. It delivers 6.4 Gb/s aggregate bandwidth across 8 data pins and integrates on-die termination (ODT), off-chip driver (OCD) impedance adjustment, and programmable CAS latency (CL = 3–6) for high-signal-integrity memory subsystems in embedded controllers and industrial SoC platforms.

For engineers reviewing the W971GG8SB-25 datasheet, W971GG8SB-25 pinout, W971GG8SB-25 application, or W971GG8SB-25 equivalent, key selection considerations include its WBGA-60 package compatibility, SSTL_18 interface compliance, tRCD/tRP/tRC timing requirements at 400 MHz, and support for auto-precharge, self-refresh, and differential DQS strobing in source-synchronous read/write operations.

Technical Context

This DDR2 SDRAM implements a double-data-rate architecture with DLL-aligned DQ/DQS transitions synchronized to differential CLK/CLK inputs. It supports burst lengths of 4 or 8, posted CAS with additive latency (AL = 0–2), and write latency WL = RL − 1, enabling efficient command/data bus utilization in multi-bank interleaved access patterns.

Functional control includes mode register (MR) and three extended mode registers (EMR1–EMR3) for configuring ODT states, OCD calibration, DLL enable/disable, RDQS/DQS differential strobe mode, and temperature-compensated refresh intervals. All commands are sampled on the crossing of CLK rising and CLK falling edges, and I/Os operate under SSTL_18 voltage thresholds with VREF referenced to VDDQ/2.

Key Specifications

Pinout & Package

W971GG8SB-25 uses a 60-ball WBGA package with 8×12.5 mm² footprint and 0.8 mm ball pitch. Power and ground balls are distributed across corners and edges to minimize noise coupling; VDDQ/VSSQ pairs isolate I/O power domains, while VDDL/VSSDL separately supply the DLL circuitry.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H128M8HQ-25E and IS42S16160F-25BLI, W971GG8SB-25 offers optimized cost and layout efficiency for 8-bit DDR2 interfaces within commercial temperature range, with unique OCD calibration for signal integrity tuning not available in the Micron part and superior flexibility versus the ISSI part's fixed-impedance design.

Availability

W971GG8SB-25 is available at Aetrix Electronics and suitable for industrial HMI controllers, network edge routers, medical imaging gateways, and automated test equipment requiring stable component supply with consistent parametric performance across production lots.

Supply support for W971GG8SB-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 solutions including NOR/NAND Flash, SRAM, and DDR SDRAM for industrial, automotive, and computing markets.

W971GG8SB-25 belongs to Winbond's DDR2 SDRAM product line designed for cost-sensitive, thermally constrained embedded systems requiring JEDEC-compliant DDR2-800 performance with enhanced signal integrity features like OCD and configurable ODT.

FAQ

What is the maximum operating frequency supported by W971GG8SB-25?

W971GG8SB-25 supports DDR2-800 operation, meaning it operates at a 400 MHz clock frequency with effective data transfer rates of 800 MT/s per pin. This is confirmed in the datasheet's Order Information table and KEY PARAMETERS section, where the -25 speed grade is explicitly rated for DDR2-800 (5-5-5) or DDR2-800 (6-6-6) timing. The device achieves this using a differential CLK/CLK input and DLL-aligned DQ/DQS timing.

Does W971GG8SB-25 support on-die termination (ODT) and how is it controlled?

Yes, W971GG8SB-25 supports on-die termination (ODT) via the dedicated ODT pin (Ball F9). When ODT is registered HIGH, internal termination resistors are enabled on DQ and DQS lines to suppress signal reflections. ODT configuration is further refined through Extended Mode Register 1 (EMR1), allowing dynamic control of termination strength during read/write cycles - a key feature for maintaining signal integrity in high-speed DDR2 designs.

What package type and ball count does W971GG8SB-25 use?

W971GG8SB-25 uses a 60-ball Wafer-Level Ball Grid Array (WBGA) package measuring 8 mm × 12.5 mm with 0.8 mm ball pitch. This is documented in Section 2 (Features) and Section 12 (Package Specification) of the datasheet. The package is lead-free and RoHS compliant, with dedicated VDDQ/VSSQ and VDDL/VSSDL power/ground pairs to isolate I/O and DLL domains.

Can W971GG8SB-25 operate in self-refresh mode, and what is its typical current draw?

Yes, W971GG8SB-25 supports self-refresh mode to maintain data retention during system sleep or low-power states. According to the Electrical Characteristics table (Section 10.9), its maximum self-refresh current (IDD6) is 8 mA at case temperatures ≤ 85°C. This low quiescent current enables extended battery-backed operation in portable medical or industrial devices without compromising memory retention.

What is the purpose of the DM/RDQS pin (Ball B3) on W971GG8SB-25?

The DM/RDQS pin on W971GG8SB-25 serves dual functions: as Data Mask (DM) during write operations and as Read Data Strobe (RDQS) when enabled via EMR(1)[A11]. As DM, it masks individual bytes of incoming write data on both edges of DQS. As RDQS, it provides a differential strobe for read data when differential DQS mode is active - enhancing timing margin in high-noise environments. Its dual-role design conserves ball count while supporting flexible interface configurations.