Winbond Electronics Corporation W9825G6EH-6

Overview

W9825G6EH-6 from Winbond Electronics is a 4M × 4 banks × 16-bit synchronous DRAM (SDRAM) operating at 166 MHz with CAS Latency 3 or 133 MHz with CAS Latency 2, supporting burst lengths of 1/2/4/8/full page, and packaged in 54-pin TSOP II (400 mil). It delivers up to 166 million words per second for embedded main memory in industrial controllers and legacy computing systems.

For engineers reviewing the W9825G6EH-6 datasheet, W9825G6EH-6 pinout, W9825G6EH-6 application, or W9825G6EH-6 equivalent, key selection considerations include its 3.3V LVTTL interface, programmable mode register for burst/latency configuration, bank interleaving capability, self-refresh and power-down modes, and industrial temperature support (0°C to 70°C).

Technical Context

This SDRAM implements fully synchronous operation synchronized to the rising edge of CLK, with command decoding controlled by CS, RAS, CAS, and WE. It features four independent memory banks enabling interleaved access to hide precharge delays and sustain high throughput across sequential or interleave burst patterns.

The device supports programmable burst types (sequential or interleave), auto-precharge via A10 assertion, and dual DQM masking (LDQM/UDQM) for byte-level write control. Its internal architecture includes a refresh counter, column address counter, and mode register that defines latency, burst length, and burst type - all configurable without external logic.

Key Specifications

Pinout & Package

W9825G6EH-6 is housed in a 54-pin TSOP II package (400 mil body width, 0.80 mm pitch), with separate VCC/VSS and VCCQ/VSSQ supplies for core logic and I/O buffers to reduce noise coupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS42S16400F-6BLI and MT48LC4M16A2P-6A, W9825G6EH-6 offers identical functional and pinout compatibility for 166 MHz SDRAM use cases but with lower standby current and Winbond-specific initialization sequences - making it optimal for cost-sensitive, thermally moderate industrial applications where vendor lock-in is not required.

Availability

W9825G6EH-6 is available at Aetrix Electronics and suitable for industrial PLCs, legacy PC main memory upgrades, medical diagnostic equipment, network appliance packet buffering, and embedded controller memory expansion requiring stable component supply over extended production lifecycles.

Supply support for W9825G6EH-6 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 over 30 years of DRAM design heritage.

The W9825G6EH series belongs to Winbond's legacy SDRAM product line, engineered for cost-effective, pin-compatible replacement in industrial and embedded systems requiring JEDEC-compliant synchronous DRAM with proven reliability and broad controller support.

FAQ

What is the maximum operating frequency and CAS latency supported by W9825G6EH-6?

W9825G6EH-6 supports two speed modes: 166 MHz with CAS Latency 3, or 133 MHz with CAS Latency 2. These are fixed speed-grade configurations defined at manufacturing; the device does not support dynamic switching between them. The mode register must be programmed accordingly during initialization to match the selected clock frequency and latency setting.

Does W9825G6EH-6 require external refresh circuitry?

No, W9825G6EH-6 performs internal refresh via Auto Refresh commands issued by the memory controller. It requires exactly 8,192 refresh cycles every 64 ms (tREF = 64 ms), which equates to one refresh command every 7.8125 µs on average. The SDRAM itself manages row addressing during refresh; no external row counter is needed.

Can W9825G6EH-6 operate in self-refresh mode without external clocks?

Yes, W9825G6EH-6 enters self-refresh mode when CS, RAS, CAS, and WE are held low with CKE low at the rising clock edge. Once entered, the internal oscillator sustains refresh autonomously, and CLK may be stopped. The device exits self-refresh when CKE returns high, followed by a tRFC + tXS delay before accepting new commands.

What is the purpose of separate VCCQ and VSSQ pins on W9825G6EH-6?

VCCQ and VSSQ provide isolated power and ground for the DQ input/output buffers only, decoupling I/O switching noise from the core logic supply (VCC/VSS). This separation improves signal integrity, reduces crosstalk on the 16-bit data bus, and meets JEDEC SDRAM noise immunity requirements - especially critical in high-speed burst transfers.

Is W9825G6EH-6 compatible with standard PC133 or PC166 memory controllers?

Yes, W9825G6EH-6 complies fully with JEDEC Standard No. 21-C for SDRAM and matches the timing, command set, and electrical specifications of PC133 (133 MHz/CL2) and PC166 (166 MHz/CL3) modules. Its 54-pin TSOP II footprint and LVTTL interface ensure drop-in compatibility with controllers designed for those standards, provided the mode register is configured correctly.