Winbond Electronics Corporation W971GG8KB-25

Overview

W971GG8KB-25 from Winbond Electronics is a 1G-bit DDR2 SDRAM organized as 16M × 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 signal integrity in memory subsystems used in industrial embedded controllers and legacy computing platforms.

For engineers reviewing the W971GG8KB-25 datasheet, W971GG8KB-25 pinout, W971GG8KB-25 application, or W971GG8KB-25 equivalent, key selection criteria include CAS latency support (CL=3–6), tRCD/tRP = 12.5 ns minimum, burst length options (4/8), OCD impedance adjustment capability, and WBGA-60 package compatibility with DDR2 memory channel layout constraints.

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 to read data and center-aligned to write data. It supports posted CAS (AL=0–2) to decouple command bus utilization from latency, and uses DLL-based clock-to-strobe alignment for timing closure at 400 MHz data rates.

Functional operation includes auto-precharge for both read and write bursts, programmable ODT states via EMR(1), OCD calibration for output driver impedance tuning, and dual power-down modes (precharged and active) to reduce IDD during idle cycles. Refresh is managed via Auto Refresh (tRFC = 57.5 ns min) or Self Refresh (IDD6 ≤ 8 mA at TCASE ≤ 85°C).

Key Specifications

Pinout & Package

W971GG8KB-25 is packaged in a lead-free, RoHS-compliant WBGA-60 (8 mm × 12.5 mm) ball grid array with 0.8 mm pitch. Ball assignment follows JEDEC-standard DDR2 layout with dedicated VDDQ/VSSQ planes and isolated DLL power (VDDL/VSSDL).

Key Features

Applications

Equivalent & Alternatives

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

Compared with W971GG8KB-25, MT47H128M8HQ-25E offers mechanical drop-in replacement in TSOP but forfeits OCD/ODT tuning; IS42S16160F-25BLI doubles data width at same speed but demands full bus-width redesign-making W971GG8KB-25 optimal for cost-sensitive, space-constrained 8-bit DDR2 upgrades.

Availability

W971GG8KB-25 is available at Aetrix Electronics and suitable for industrial automation, legacy networking equipment, and medical imaging systems requiring stable component supply with long-term lifecycle assurance.

Supply support for W971GG8KB-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 DRAM products for industrial, automotive, and consumer markets.

The W971GG8KB series belongs to Winbond's DDR2 SDRAM product line, designed specifically for cost-effective, high-reliability memory in legacy and extended-lifecycle embedded systems where DDR3/DDR4 migration is impractical.

FAQ

What is the maximum data rate supported by W971GG8KB-25?

W971GG8KB-25 supports DDR2-800 operation, delivering 800 megatransfers per second per pin. This corresponds to a 400 MHz differential clock frequency with tCK(min) = 2.5 ns at CL=5/6. The device meets JEDEC specification JESD79-2F for DDR2-800 (5-5-5 or 6-6-6) timing, validated across 0°C to 85°C case temperature.

Does W971GG8KB-25 support on-die termination (ODT)?

Yes, W971GG8KB-25 supports programmable on-die termination via the ODT pin and Extended Mode Register (EMR) configuration. When ODT is asserted HIGH, internal termination resistors (typically 75 Ω or 150 Ω depending on EMR settings) are enabled on DQ/DQS lines to suppress reflections in point-to-point or fly-by topologies-eliminating need for external termination resistors.

What package type is used for W971GG8KB-25?

W971GG8KB-25 uses a lead-free, RoHS-compliant WBGA-60 package measuring 8 mm × 12.5 mm with 0.8 mm ball pitch. The ball map follows standard DDR2 layout conventions, including dedicated VDDQ/VSSQ planes and isolated DLL power (VDDL/VSSDL) to minimize switching noise coupling into timing circuitry.

Can W971GG8KB-25 operate at CAS Latency 3?

Yes, W971GG8KB-25 supports CAS Latency 3 at DDR2-800 speed, with tCK(min) = 5 ns. This is confirmed in the datasheet's KEY PARAMETERS table under "@CL = 3" row, specifying minimum clock period of 5 ns for -25/-25I speed grades. CL=3 operation requires strict adherence to tRCD/tRP ≥ 12.5 ns and proper DLL initialization.

What is the purpose of OCD calibration in W971GG8KB-25?

OCD (Off-Chip Driver) calibration in W971GG8KB-25 adjusts output driver impedance to match transmission line characteristics, reducing signal overshoot/undershoot and improving timing margins. It is executed via EMR(1) commands during initialization and supports dynamic recalibration-critical for maintaining signal integrity across voltage and temperature variations in industrial environments.