Winbond Electronics Corporation W9712G6KB-25

Overview

W9712G6KB-25 from Winbond Electronics is a 128M-bit DDR2 SDRAM organized as 2,097,152 words × 4 banks × 16 bits, operating at 800 MT/s (DDR2-800) with CAS latency options of 3–6 and tCK(min) = 2.5 ns. It supports on-die termination (ODT), off-chip driver (OCD) impedance adjustment, and auto-precharge for embedded control and industrial display memory buffering.

For engineers reviewing the W9712G6KB-25 datasheet, W9712G6KB-25 pinout, W9712G6KB-25 application, or W9712G6KB-25 equivalent, key selection considerations include DDR2-800 timing compliance (5-5-5/6-6-6), TFBGA-84 ball layout, SSTL_18 interface compatibility, and industrial-grade thermal margin up to 85°C case temperature.

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. DLL alignment ensures precise DQ–DQS timing, while posted CAS (AL = 0–2) enables command bus efficiency without sacrificing latency predictability.

Functional operation relies on four independent banks, each supporting active–precharge–refresh sequences governed by JEDEC-standard tRCD (≥12.5 ns), tRP (≥12.5 ns), and tRC (≥57.5 ns) timing. ODT and OCD are programmable via extended mode registers (EMR1–EMR3), enabling dynamic signal integrity tuning during system initialization and runtime.

Key Specifications

Pinout & Package

W9712G6KB-25 is packaged in an 84-ball TFBGA (8 mm × 12.5 mm) with ball pitch of 0.8 mm. The package features separate power domains (VDD, VDDQ, VDDL), dedicated DQ ground (VSSQ), and differential clock (CLK/CLK) and strobe (UDQS/UDQS, LDQS/LDQS) pairs for source-synchronous timing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H128M16HR-25E, W9712G6KB-25 offers smaller footprint (84 vs. 96 balls) and integrated OCD calibration, reducing layout sensitivity; versus IS42S16160F-6BL, it delivers 20% higher bandwidth and industrial temperature support, at the cost of more complex register programming.

Availability

W9712G6KB-25 is available at Aetrix Electronics and suitable for industrial HMI display buffering, network packet queuing, and medical imaging control requiring stable component supply across multi-year production cycles.

Supply support for W9712G6KB-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.

The W97 series targets cost-optimized, high-reliability DDR2 applications in space-constrained embedded systems, emphasizing JEDEC compliance, thermal robustness, and simplified power sequencing.

FAQ

What is the minimum clock period supported by W9712G6KB-25 at CAS Latency 5?

The W9712G6KB-25 supports a minimum clock period (tCK) of 2.5 ns at CAS Latency 5, corresponding to a DDR2-800 data rate of 800 MT/s. This value is specified in the KEY PARAMETERS table for the -25 speed grade and is validated across the full 0°C to 85°C case temperature range. The W9712G6KB-25 must be operated within this timing constraint to meet JEDEC DDR2-800 (5-5-5) specifications.

Does W9712G6KB-25 support differential DQS operation, and how is it enabled?

Yes, W9712G6KB-25 supports differential DQS operation using UDQS/UDQS and LDQS/LDQS pairs. It is enabled by setting bit A10 HIGH in the Extended Mode Register 1 (EMR1) via an EMRS command. When enabled, both upper- and lower-byte strobes operate in differential mode, providing improved jitter tolerance and skew margin over single-ended implementations. The W9712G6KB-25 defaults to single-ended mode unless explicitly configured otherwise during initialization.

What is the purpose of the VDDL and VSSDL pins on W9712G6KB-25, and how should they be routed?

VDDL and VSSDL supply dedicated power and ground to the internal DLL circuitry in W9712G6KB-25. They must be decoupled independently from VDD/VSS and VDDQ/VSSQ using low-ESR capacitors (typically 100 nF + 10 µF) placed near the ball. Routing requires short, direct traces with solid ground planes beneath to minimize DLL phase noise and ensure stable DQ–DQS alignment. The W9712G6KB-25 specification mandates |VDD − VDDL| ≤ 0.3 V during ramp and stable regulation within ±0.1 V during operation.

How does OCD calibration function in W9712G6KB-25, and when must it be performed?

OCD calibration in W9712G6KB-25 adjusts the drive strength of DQ and DQS output buffers to match PCB trace impedance, typically 50 Ω. It is executed after DLL enable and reset during power-up initialization, requiring ≥200 clock cycles post-DLL reset. If skipped, EMR(1) must be programmed with default OCD values (A9=A8=A7=HIGH then LOW). The W9712G6KB-25 specification defines OCD as mandatory for optimal signal integrity at 800 MT/s, especially in multi-drop or long-trace layouts.

Can W9712G6KB-25 operate in Self Refresh mode at 95°C case temperature?

No, W9712G6KB-25 is rated for 0°C ≤ TCASE ≤ 85°C and does not guarantee Self Refresh operation at 95°C. While the -25I variant supports 95°C with doubled refresh rate (tREFI = 7.8 µS) and EMR(2) bit A7 = 1, the W9712G6KB-25 lacks industrial-grade qualification and thermal validation beyond 85°C. Operating W9712G6KB-25 above 85°C risks data retention failure and violates its JEDEC specification compliance.