Winbond Electronics Corporation W9725G6KB-25 TR

Overview

W9725G6KB-25 TR from Winbond is a 256Mb (4M × 4 banks × 16-bit) DDR2 SDRAM compliant with DDR2-800 (5-5-5 or 6-6-6) timing, operating at 1.8 V ± 0.1 V supply, supporting CAS latencies of 3–7 and burst lengths of 4/8 for embedded memory buffering in industrial controllers and network interface cards.

For engineers reviewing the W9725G6KB-25 TR datasheet, W9725G6KB-25 TR pinout, W9725G6KB-25 TR application, or W9725G6KB-25 TR equivalent, key selection considerations include tRCD/tRP = 12.5 ns minimum, ODT programmability via EMR(1), OCD impedance calibration support, and WBGA-84 ball layout with differential clock (CLK/CLK) and dual DQS strobes (UDQS/LDQS).

Technical Context

This DDR2 SDRAM implements a 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), auto-precharge, and on-die termination (ODT) controlled by dedicated ODT pin and EMR settings.

The device integrates four independent 64Mb banks, each with row/column decoders, sense amplifiers, and prefetch buffers. Its command decoder interprets CS/RAS/CAS/WE combinations on every rising CLK edge, enabling bank activate, read/write, precharge, refresh, and power-down operations per JEDEC DDR2 specification.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with W9725G6KB-25 TR, MT47H64M16HR-25E:H offers automotive qualification but requires register initialization changes, while IS42S16160F-25BLI provides industrial temp assurance and tighter tRFC but needs ODT timing validation in existing designs.

Availability

W9725G6KB-25 TR is available at Aetrix Electronics and suitable for industrial automation, network infrastructure, and medical imaging systems requiring stable component supply, long-lifecycle support, and RoHS-compliant DDR2 memory solutions.

Supply support for W9725G6KB-25 TR 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, flash, and logic ICs, with global manufacturing and quality certifications including ISO 9001 and IATF 16949.

The W9725G6KB series belongs to Winbond's DDR2 SDRAM product line, designed specifically for cost-sensitive, thermally constrained embedded systems needing JEDEC-compliant high-bandwidth memory with low standby power.

FAQ

What is the maximum operating frequency supported by the W9725G6KB-25 TR?

The W9725G6KB-25 TR is rated for DDR2-800 operation, meaning it supports a 400 MHz clock frequency with 800 MT/s data transfer rate. This corresponds to a minimum tCK of 2.5 ns at CL=5 or CL=6, and is validated across the full commercial temperature range (0°C to 85°C). The W9725G6KB-25 TR does not support DDR2-1066 or DDR2-667 speed grades - those require distinct part numbers (-18 or -3 suffixes).

Does the W9725G6KB-25 TR support on-die termination (ODT), and how is it controlled?

Yes, the W9725G6KB-25 TR supports on-die termination via a dedicated ODT pin (Ball K9) and Extended Mode Register EMR(1). When ODT is asserted HIGH on the pin, internal termination resistors (75 Ω or 150 Ω, configurable via EMR) are enabled on DQ/DQS lines. This eliminates need for external termination resistors and improves signal integrity in point-to-point topologies. The W9725G6KB-25 TR requires proper EMR(1) programming during initialization to set ODT resistance value and enable mode.

What package type and ball count does the W9725G6KB-25 TR use?

The W9725G6KB-25 TR uses a WBGA-84 package measuring 8 mm × 12.5 mm with lead-free, RoHS-compliant construction. It has 84 solder balls arranged in a rectangular grid (8×12.5 mm² footprint), including dedicated VDDQ/VSSQ planes for I/O noise isolation and separate VDD/VSS for core logic. Pinout matches JEDEC-standard DDR2 SDRAM ball assignment for WBGA-84, ensuring compatibility with standard DDR2 layout guidelines.

Can the W9725G6KB-25 TR operate at CAS Latency 3, and what are the timing implications?

Yes, the W9725G6KB-25 TR supports CAS Latency 3 at DDR2-800 speed, with minimum tCK = 5.0 ns. At CL=3, read latency (RL) becomes AL + CL, so RL=3 with AL=0 yields shortest possible read response. However, tRCD and tRP remain fixed at 12.5 ns minimum - meaning the W9725G6KB-25 TR cannot issue a READ command until 12.5 ns after ACTIVATE, regardless of CL setting. This constraint governs minimum random-access performance in bank-interleaved configurations.

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

No, the W9725G6KB-25 TR is not pin-compatible with the W9725G6KB-25I variant. While both share identical WBGA-84 packaging and ball assignment, the -25I version is specified for industrial temperature range (−40°C to 95°C) and undergoes additional screening - but more critically, its ODT timing parameters and self-refresh current (IDD6) differ per datasheet revision. Interchangeability requires full electrical and thermal validation; the W9725G6KB-25 TR must be used strictly within its 0°C to 85°C operating envelope.