Winbond Electronics Corporation W9751G6KB25I

Overview

W9751G6KB25I from Winbond is a 512Mb (8M × 4 banks × 16-bit) DDR2 SDRAM operating at DDR2-800 speed (5-5-5 or 6-6-6 timing), with 1.8V VDD/VDDQ supply, industrial temperature range (–40°C to +95°C), and on-die termination (ODT) for signal integrity in embedded memory subsystems used in networking routers and industrial HMIs.

For engineers reviewing the W9751G6KB25I datasheet, W9751G6KB25I pinout, W9751G6KB25I application, or W9751G6KB25I equivalent, key selection criteria include its -25I speed grade compliance, 84-ball WBGA package, SSTL_18 interface compatibility, ODT programmability, and support for CAS latencies 3–7 with auto-precharge and self-refresh modes.

Technical Context

This DDR2 SDRAM uses differential clock inputs (CLK/CLK) with command latching at clock crossings and source-synchronous DQS/DQS strobes aligned edge-to-read and center-to-write data. Its DLL aligns DQ and DQS transitions to minimize skew across the data bus.

The device implements four independent banks with bank-select inputs (BA0/BA1), supports posted CAS (AL = 0–2), and provides OCD impedance calibration for off-chip driver tuning. It executes auto-refresh and self-refresh with tREFI as low as 3.9 µS at 85–95°C when A7=1 in EMR(2).

Key Specifications

Pinout & Package

Package: 84-ball WBGA (8 mm × 12.5 mm), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H64M4HQ-25E and IS42S16400F-25BLI, the W9751G6KB25I uniquely combines 84-ball WBGA compactness, differential DQS support, and full OCD/ODT configurability - making it optimal for new industrial designs demanding signal integrity and thermal resilience without footprint compromise.

Availability

W9751G6KB25I is available at Aetrix Electronics and suitable for networking infrastructure, industrial HMI, medical imaging controllers, and smart energy gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W9751G6KB25I 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 and microcontrollers, with over 30 years of DRAM design heritage and JEDEC-compliant manufacturing.

The W9751G6KB25I belongs to Winbond's industrial-grade DDR2 SDRAM product line, engineered for reliability in thermally demanding embedded systems where consistent timing, low-power refresh, and signal integrity are critical.

FAQ

What is the maximum supported CAS latency for W9751G6KB25I?

The W9751G6KB25I supports CAS latency (CL) values of 3, 4, 5, 6, and 7. At DDR2-800 speed (–25I grade), CL=5 and CL=6 are the most commonly used settings, with tCK min = 2.5 ns. CL=7 is supported but requires longer tRCD/tRP delays per JEDEC specification and is typically reserved for margin testing or derated operation.

Does W9751G6KB25I support differential DQS operation?

Yes, the W9751G6KB25I supports differential DQS operation via UDQS/UDQS and LDQS/LDQS pins. This mode is enabled by setting A10=1 in the EMR(1) register. When active, both upper and lower byte strobes operate differentially, improving jitter tolerance and signal integrity in high-noise industrial environments.

How is self-refresh configured for high-temperature operation in W9751G6KB25I?

For operation at 85–95°C, the W9751G6KB25I requires tREFI = 3.9 µS (doubled refresh rate). This is enabled by setting bit A7 = 1 in EMR(2) during initialization. The device then enters self-refresh automatically when CKE is held LOW, maintaining data retention with IDD6 ≤ 6 mA even at 95°C case temperature.

What is the purpose of the VSSDL and VDDL pins on W9751G6KB25I?

VSSDL and VDDL are dedicated ground and power supply pins for the internal delay-locked loop (DLL). Isolating the DLL's analog circuitry from core digital and I/O supplies minimizes noise coupling and ensures stable DQ–DQS alignment across voltage and temperature variations - a critical requirement for DDR2 timing compliance.

Can W9751G6KB25I be used in place of a DDR2-1066 part like W9751G6KB18I?

No - the W9751G6KB25I is rated for DDR2-800 (tCK min = 2.5 ns), while the W9751G6KB18I supports DDR2-1066 (tCK min = 1.875 ns). Substituting the -25I for the -18I will violate setup/hold timing in systems designed for 1066 MT/s, causing read/write failures. They share the same package and command set but are not speed-interchangeable.