Winbond Electronics Corporation W9725G8KB-18 TR

Overview

W9725G8KB-18 TR from Winbond Electronics is a 256Mbit DDR2 SDRAM organized as 8,388,608 words × 4 banks × 8 bits, operating at 1.8 V ± 0.1 V with DDR2-1066 (7-7-7) timing, CAS latency 3–7, and burst lengths of 4 or 8. It supports on-die termination (ODT), off-chip driver (OCD) impedance adjustment, and auto-precharge for embedded memory subsystems in industrial controllers and network edge devices.

For engineers reviewing the W9725G8KB-18 TR datasheet, W9725G8KB-18 TR pinout, W9725G8KB-18 TR application, or W9725G8KB-18 TR equivalent, key selection criteria include tRCD/tRP = 13.125 ns minimum, IDD0 ≤ 70 mA, SSTL_18 interface compatibility, WBGA-60 package mechanical fit, and DDR2-1066 signal integrity requirements including DQS center-aligned write timing and DLL-aligned read capture.

Technical Context

The W9725G8KB-18 TR 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. Its internal DLL aligns DQ transitions to clock edges, enabling reliable 533 MHz operation (tCK = 1.875 ns min at CL=7).

Command decoding uses CS, RAS, CAS, and WE sampled on CLK crossings; address A0–A12 and bank select BA0–BA1 configure row/column access and mode register targeting. Extended Mode Registers (EMR1–EMR3) control ODT enable/disable, OCD calibration, additive latency, and differential strobe configuration-critical for signal integrity in high-speed PCB layouts.

Key Specifications

Pinout & Package

Packaged in RoHS-compliant, lead-free WBGA-60 (8 mm × 12.5 mm, 0.8 mm pitch), with isolated VSSQ and VSSDL planes for DQ and DLL noise suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H64M4BP-37E:H and IS42S32800F-6BLI, the W9725G8KB-18 TR provides superior signal integrity control via programmable ODT and OCD calibration, tighter tRCD/tRP (13.125 ns vs. 15 ns), and guaranteed DDR2-1066 performance - making it optimal for new industrial and networking designs demanding minimal layout iteration and maximum timing margin.

Availability

W9725G8KB-18 TR is available at Aetrix Electronics and suitable for industrial PLCs, network edge routers, medical imaging systems, and automotive ADAS camera modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for W9725G8KB-18 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 solutions, including NOR/NAND Flash, SRAM, and DDR SDRAM products for industrial, communications, and consumer markets.

The W9725G8KB series belongs to Winbond's industrial-grade DDR2 SDRAM product line, designed specifically for applications requiring extended temperature operation, robust signal integrity features (ODT/OCD), and JEDEC-compliant DDR2-1066 performance in space-constrained embedded systems.

FAQ

What is the maximum clock frequency supported by the W9725G8KB-18 TR?

The W9725G8KB-18 TR supports DDR2-1066 operation with a maximum clock frequency of 533 MHz (tCK = 1.875 ns minimum at CL=7). This is validated across the full 0°C to +85°C case temperature range and requires strict adherence to AC timing parameters including tRCD ≥ 13.125 ns and tRP ≥ 13.125 ns. The device does not support overclocking beyond this rated speed grade.

Does the W9725G8KB-18 TR support on-die termination (ODT) and how is it configured?

Yes, the W9725G8KB-18 TR supports programmable on-die termination (ODT) via the ODT pin (ball F9) and Extended Mode Register EMR(1). When ODT is asserted HIGH, internal termination resistors (75 Ω or 150 Ω, configurable via EMR) are enabled on DQ and DQS lines. This eliminates the need for external termination resistors and improves signal integrity in point-to-point DDR2 interfaces - a key feature confirmed in the device's functional description and electrical characteristics tables.

What package type and dimensions does the W9725G8KB-18 TR use?

The W9725G8KB-18 TR uses a RoHS-compliant, lead-free WBGA-60 package measuring 8 mm × 12.5 mm with 0.8 mm ball pitch. Pinout follows the standard DDR2 SDRAM ball map defined in section 5 of the datasheet, including dedicated VSSQ and VSSDL grounds for DQ and DLL noise isolation. This package is compatible with standard reflow profiles for Pb-free assembly.

Can the W9725G8KB-18 TR operate at CAS latency 3, and what are the timing implications?

Yes, the W9725G8KB-18 TR supports CAS latency 3 at lower frequencies (e.g., DDR2-667), but not at its rated DDR2-1066 speed grade. At CL=3, the minimum tCK is 5 ns - incompatible with the -18 speed grade's 1.875 ns tCK requirement. CL=3 operation is only valid for -3 speed grade parts; using CL=3 on W9725G8KB-18 TR would violate tRCD and tRP timing margins and is not supported per the KEY PARAMETERS table.

How does the W9725G8KB-18 TR handle power management during system idle periods?

The W9725G8KB-18 TR supports multiple low-power modes: Precharged Power Down (CKE-driven, IDD ≤ 15 mA), Active Power Down (banks active, IDD ≤ 35 mA), and Self Refresh (IDD6 ≤ 6 mA at TCASE ≤ 85°C). These modes are entered via CKE deactivation and specific command sequences documented in section 8.9. Self Refresh maintains data retention without external refresh commands - critical for battery-backed industrial and automotive applications.