Winbond Electronics Corporation W9725G8KB-25

Overview

W9725G8KB-25 from Winbond is a 256M-bit DDR2 SDRAM organized as 8,388,608 words × 4 banks × 8 bits, operating at DDR2-800 speed (5-5-5 or 6-6-6 timing), with 1.8 V ± 0.1 V supply, CAS latency options of 3–7, and burst lengths of 4 or 8 - deployed in embedded control, industrial HMIs, and legacy networking equipment requiring pin-compatible DDR2 memory replacement.

For engineers reviewing the W9725G8KB-25 datasheet, W9725G8KB-25 pinout, W9725G8KB-25 application, or W9725G8KB-25 equivalent, this page delivers verified DDR2-800 timing compliance, OCD/ODT configuration support, SSTL_18 interface compatibility, and WBGA-60 package details essential for signal integrity validation and board-level integration.

Technical Context

This DDR2 SDRAM implements double-data-rate architecture synchronized to differential CLK/CLK inputs, with DLL-aligned DQ/DQS timing and source-synchronous I/O referenced to both edges of DQS. It supports posted CAS (AL = 0–2), additive latency (RL = AL + CL), and write latency WL = RL − 1.

Functional operation includes on-die termination (ODT) controlled via dedicated ODT pin, off-chip driver (OCD) impedance calibration using EMR(1), auto-precharge for read/write bursts, and dual power-down modes (precharged and active). Refresh is managed via Auto Refresh and Self Refresh with IDD6 ≤ 6 mA at TCASE ≤ 85°C.

Key Specifications

Pinout & Package

W9725G8KB-25 uses an 8 mm × 12.5 mm WBGA-60 package with 0.8 mm ball pitch, RoHS-compliant lead-free construction, and isolated VSSQ/VSSDL planes for DQ and DLL noise immunity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H64M4BP-25E and IS42S16400F-25BLI, W9725G8KB-25 uniquely combines WBGA-60 compactness, pin-controlled ODT, and OCD calibration - enabling direct drop-in replacement in space-constrained industrial designs without sacrificing signal integrity tuning capability.

Availability

W9725G8KB-25 is available at Aetrix Electronics and suitable for industrial HMIs, legacy networking switches, and medical diagnostic displays requiring stable component supply, long-lifecycle support, and guaranteed DDR2-800 timing compliance.

Supply support for W9725G8KB-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.

W9725G8KB-25 belongs to Winbond's DDR2 SDRAM product line, designed specifically for cost-sensitive, long-lifecycle industrial applications where reliability, thermal robustness, and pin-compatible migration from earlier DDR2 generations are critical.

FAQ

What DDR2 speed grade does W9725G8KB-25 support?

W9725G8KB-25 supports DDR2-800 operation at 400 MHz clock frequency, compliant with either 5-5-5 or 6-6-6 timing binning. Its tCK(avg) ranges from 2.5 ns (CL=5/6) to 5 ns (CL=3), and it meets all AC/DC electrical specifications defined for DDR2-800 in JEDEC JESD79-2F. The -25 suffix explicitly denotes this speed grade.

Does W9725G8KB-25 support on-die termination (ODT)?

Yes, W9725G8KB-25 supports ODT via a dedicated ODT input pin (ball F9). When asserted HIGH, it enables internal termination resistors on DQ and DQS lines. ODT states are configurable per bank and can be dynamically enabled/disabled during operation - critical for point-to-point and multi-drop DDR2 topologies.

What is the package type and ball count of W9725G8KB-25?

W9725G8KB-25 uses a WBGA-60 package: 8 mm × 12.5 mm body size, 0.8 mm ball pitch, 60 solder balls arranged in an 8×8 grid with corner balls omitted. It is RoHS-compliant and lead-free, with separate VSSQ and VSSDL grounds for improved DQ and DLL noise isolation.

Can W9725G8KB-25 operate with CAS latency 3?

Yes, W9725G8KB-25 supports CAS latency 3 at DDR2-800 speed, with minimum tRCD and tRP of 12.5 ns. CL=3 operation requires tCK ≥ 5 ns (200 MHz clock), and is validated for use in applications prioritizing low-latency access over maximum bandwidth - such as real-time control buffers.

How is OCD calibration performed on W9725G8KB-25?

OCD calibration on W9725G8KB-25 is executed via Extended Mode Register Set (EMRS) commands to EMR(1), using address pins A9–A7 to enter/exit calibration mode and adjust drive strength. The process must occur ≥200 clocks after DLL reset and is required to optimize DQ output impedance matching to PCB trace characteristics.