Winbond Electronics Corporation W971GG8JB25I

Overview

W971GG8JB25I from Winbond Electronics is a 1G-bit DDR2 SDRAM organized as 16M × 8 banks × 8 bits, supporting DDR2-800 (5-5-5) speed grade with CAS latency 3–7, 1.8 V supply, and industrial temperature range of −40°C to +95°C. It delivers 800 Mb/sec/pin data rates and integrates on-die termination (ODT), off-chip driver (OCD) impedance adjustment, and differential DQS strobes for high-signal-integrity memory subsystems in embedded controllers and industrial HMIs.

For engineers reviewing the W971GG8JB25I datasheet, W971GG8JB25I pinout, W971GG8JB25I application, or W971GG8JB25I equivalent, key selection criteria include its industrial-grade thermal specification, SSTL_18 interface compliance, WBGA60 package compatibility, and support for posted CAS, auto-precharge, and self-refresh modes across extended temperature operation.

Technical Context

This DDR2 SDRAM uses a double-data-rate architecture synchronized to differential CLK/CLK inputs, with all commands latched on clock crossings. Its internal DLL aligns DQ and DQS transitions to the clock, enabling precise timing at 250 MHz (tCK = 4 ns min at CL=5). The device implements eight independent banks and supports burst lengths of 4 or 8, with programmable additive latency (AL = 0–2) to optimize command bus efficiency.

Functional control is managed via Mode Register (MR) and three Extended Mode Registers (EMR1–EMR3), configuring ODT resistance, OCD calibration, DLL enable/disable, RDQS/DQS mode, and high-temperature self-refresh activation. Refresh intervals are dynamically adjusted per JEDEC: 7.8 µs at ≤85°C and halved to 3.9 µs above 85°C, requiring EMR(2) A7=1 for TCASE >85°C operation.

Key Specifications

Pinout & Package

W971GG8JB25I is housed in a lead-free, RoHS-compliant WBGA60 package (8 mm × 12.5 mm, 1.0 mm height), with ball pitch of 0.8 mm. The package supports standard PCB assembly and provides dedicated VDDQ/VSSQ planes for I/O power integrity.

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, W971GG8JB25I offers unique OCD calibration and RDQS capability for advanced signal integrity tuning, while maintaining identical industrial thermal performance and DDR2-800 timing - making it optimal for noise-sensitive, long-trace, or mixed-technology PCB designs.

Availability

W971GG8JB25I is available at Aetrix Electronics and suitable for industrial HMIs, embedded networking gateways, ruggedized medical displays, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W971GG8JB25I 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 DRAM products for industrial, automotive, and communications markets.

The W971GG8JB series belongs to Winbond's industrial-grade DDR2 SDRAM product line, designed specifically for applications demanding guaranteed operation across −40°C to +95°C with full JEDEC compliance and enhanced signal integrity features like OCD and RDQS.

FAQ

What is the maximum operating frequency supported by W971GG8JB25I?

W971GG8JB25I supports DDR2-800 operation, meaning it runs at a 400 MHz clock frequency with effective data transfer rates of 800 Mb/sec/pin. Its minimum clock period (tCK) is 2.5 ns at CAS Latency 5, confirmed in the datasheet's KEY PARAMETERS table for the -25I speed grade. This frequency is fully guaranteed across the entire −40°C to +95°C case temperature range.

Does W971GG8JB25I support on-die termination (ODT), and how is it controlled?

Yes, W971GG8JB25I supports programmable on-die termination (ODT) via the ODT pin (Ball F9) and Extended Mode Register EMR(1). When ODT is asserted HIGH, internal termination resistors are enabled on DQ and DQS lines. Resistance values are configured through EMR(1) bits A1–A0, allowing selection among 75 Ω, 150 Ω, or 50 Ω options - critical for impedance-matched routing without external resistors.

How does W971GG8JB25I handle refresh at elevated temperatures?

W971GG8JB25I complies with JEDEC DDR2 requirements for high-temperature refresh: when case temperature exceeds +85°C, the refresh interval must halve from 7.8 µs to 3.9 µs. This is enabled by setting bit A7 = 1 in EMR(2), which activates high-temperature self-refresh mode. The device then automatically doubles refresh command frequency while remaining in self-refresh, ensuring data retention up to +95°C.

What is the purpose of the DM/RDQS pin (Ball B3) on W971GG8JB25I?

The DM/RDQS pin on W971GG8JB25I serves dual functions: as DM (Data Mask) during write operations to suppress individual byte writes, or as RDQS (Read Data Strobe) during reads when enabled via EMR(1) bit A11 = 1. When RDQS is active, it operates differentially with RDQS (Ball A2) to provide a dedicated read strobe - improving timing margin in high-noise environments where DQS may be compromised.

Is W971GG8JB25I pin-compatible with other speed grades in the W971GG8JB family?

Yes, W971GG8JB25I shares identical WBGA60 package dimensions, ball map, and pin functions with all other W971GG8JB variants (e.g., -18, -25, -3, 25A, 25K). The only differences are speed binning, temperature grading, and associated AC timing parameters - enabling drop-in replacement across grades where system timing margins allow, without PCB or layout changes.