Winbond Electronics Corporation W9725G6KB25I

Overview

W9725G6KB25I from Winbond is a 256Mb (4M × 4 banks × 16-bit) DDR2 SDRAM supporting DDR2-800 speed grade with CL=5/6, tRCD/tRP = 12.5 ns minimum, and industrial temperature range of –40°C to +95°C. It features on-die termination (ODT), off-chip driver (OCD) impedance adjustment, DLL-aligned DQ/DQS timing, and SSTL_18 interface for high-signal-integrity memory subsystems in embedded controllers and networking equipment.

For engineers reviewing the W9725G6KB25I datasheet, W9725G6KB25I pinout, W9725G6KB25I application, or W9725G6KB25I equivalent, key selection considerations include its industrial-grade thermal rating, DDR2-800 timing compliance (5-5-5 or 6-6-6), 84-ball WBGA package, ODT/OCD programmability, and support for burst lengths of 4/8 with posted CAS and auto-precharge.

Technical Context

This DDR2 SDRAM uses a double-data-rate architecture synchronized to differential CLK/CLK inputs, with bi-directional DQS/DQS strobes edge-aligned on reads and center-aligned on writes. Its internal DLL ensures precise DQ-to-DQS alignment, while EMR-controlled ODT and OCD allow dynamic signal integrity tuning per system layout.

Command decoding is fully synchronous with address and control inputs latched on CLK/CLK crossings; all operations-including bank activate, read/write, precharge, refresh, and power-down modes-are governed by a state machine with defined tRCD, tRP, tRC, and tRAS timing constraints validated across –40°C to +95°C.

Key Specifications

Pinout & Package

Packaged in 84-ball WBGA (8 mm × 12.5 mm, 0.8 mm pitch), RoHS-compliant and lead-free. Ball grid includes dedicated VDDQ/VSSQ planes, isolated DLL supply (VDDL/VSSDL), reference voltage (VREF), and dual-byte DQS 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, W9725G6KB25I delivers guaranteed operation down to –40°C and matches the exact WBGA mechanical outline; versus IS42S16160F-25BLI, it shares thermal and package compatibility but requires validation of DLL reset and OCD calibration sequences in system initialization code.

Availability

W9725G6KB25I is available at Aetrix Electronics and suitable for industrial PLC controllers, network switch packet buffers, medical imaging front-end buffers, and automotive ADAS video preprocessors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W9725G6KB25I 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 W97 series targets cost-sensitive, thermally demanding DDR2 applications where industrial qualification, robust signal integrity features (ODT/OCD/DLL), and long-term supply stability are mandatory design requirements.

FAQ

What is the maximum operating frequency supported by the W9725G6KB25I?

The W9725G6KB25I is rated for DDR2-800 operation, supporting a maximum clock frequency of 400 MHz (800 MT/s data rate). This is validated under industrial conditions (–40°C to +95°C) with tCK(min) = 2.5 ns for CL=5/6 configurations. The device does not support DDR2-1066 speeds; that capability is exclusive to the -18 speed grade variant.

Does the W9725G6KB25I support on-die termination (ODT), and how is it configured?

Yes, the W9725G6KB25I supports programmable on-die termination via the ODT pin and Extended Mode Register (EMR) settings. ODT is enabled by driving the ODT pin HIGH and configuring termination resistance values (75 Ω, 150 Ω, or off) through EMR(1). This eliminates the need for external termination resistors and improves signal integrity in point-to-point and fly-by DDR2 topologies.

What package type and ball count does the W9725G6KB25I use?

The W9725G6KB25I uses an 84-ball Wafer-Level Ball Grid Array (WBGA) package measuring 8 mm × 12.5 mm with 0.8 mm ball pitch. It is lead-free and RoHS compliant. Pinout follows JEDEC-standard DDR2 SDRAM layout with dedicated VDDQ/VSSQ planes, differential clock (CLK/CLK), and dual-byte DQS strobes (UDQS/UDQS and LDQS/LDQS).

How does the W9725G6KB25I handle power management in embedded systems?

The W9725G6KB25I implements three low-power states: Precharged Power Down (IDD2 ≤ 25 mA), Active Power Down (IDD3 ≤ 45 mA), and Self Refresh (IDD6 ≤ 6 mA). These are controlled via CKE gating and command sequences, enabling dynamic power scaling in battery-backed or thermally constrained embedded systems without losing memory contents.

Is the W9725G6KB25I pin-compatible with other Winbond DDR2 SDRAMs like the W9725G6KB-25?

Yes, the W9725G6KB25I shares identical pinout, package dimensions, and electrical interface with the commercial-grade W9725G6KB-25. The only differences are the extended industrial temperature qualification (–40°C to +95°C vs. 0°C to +85°C) and tighter AC parameter validation across that full range-no PCB or schematic changes are required for substitution.