Winbond Electronics Corporation W971GG8SB25I TR

Overview

W971GG8SB25I TR from Winbond is a 1G-bit DDR2 SDRAM organized as 16M × 8 banks × 8 bits, operating at DDR2-800 speed (5-5-5 or 6-6-6 timing), with 1.8 V supply, industrial temperature range (−40°C to +95°C), and SSTL_18 interface - deployed in embedded networking controllers and industrial HMIs requiring reliable high-bandwidth memory buffering.

For engineers reviewing the W971GG8SB25I TR datasheet, W971GG8SB25I TR pinout, W971GG8SB25I TR application, or W971GG8SB25I TR equivalent, key selection criteria include CAS latency support (CL=3–6), on-die termination (ODT) programmability, OCD impedance calibration, differential clock (CLK/CLK) synchronization, and WBGA-60 package compatibility with JEDEC DDR2-800 layout rules.

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 data strobes (DQS/DQS). It supports posted CAS (AL=0–2), burst lengths of 4 or 8, and write latency = read latency − 1 (WL = RL − 1).

Functional operation includes auto-precharge, self-refresh, active/precharged power-down modes, and configurable ODT states via EMR(1). The device uses eight internal banks, each with independent row activation, and supports OCD calibration for precise off-chip driver impedance matching to PCB trace characteristics.

Key Specifications

Pinout & Package

W971GG8SB25I TR uses a 60-ball Wafer-Level Ball Grid Array (WBGA) package measuring 8 mm × 12.5 mm with 0.8 mm ball pitch. The package features separate power domains (VDD, VDDQ, VDDL), dedicated DQ ground (VSSQ), and differential clock inputs for robust timing margin.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT47H128M8HQ-25E IT:C and IS42S16160F-6BLI, W971GG8SB25I TR offers superior signal integrity via OCD calibration and differential DQS, lower active current (70 mA vs. 85 mA), and WBGA-60 footprint ideal for space-constrained industrial modules - making it optimal for new designs prioritizing EMI control and thermal efficiency.

Availability

W971GG8SB25I TR is available at Aetrix Electronics and suitable for industrial HMIs, network edge gateways, medical diagnostic terminals, and railway signaling modules requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for W971GG8SB25I 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, PSRAM, and DDR SDRAM for industrial and automotive markets.

W971GG8SB25I TR belongs to Winbond's DDR2 SDRAM product line, designed specifically for cost-sensitive yet thermally demanding embedded applications where reliability under extended temperature stress and JEDEC compliance are mandatory.

FAQ

What is the maximum supported CAS latency for W971GG8SB25I TR?

W971GG8SB25I TR supports programmable CAS latency values of CL = 3, 4, 5, or 6. At DDR2-800 speed (400 MHz clock), CL = 6 corresponds to a 15 ns delay (6 × 2.5 ns), while CL = 3 yields the lowest access latency of 7.5 ns. These settings are configured via the Mode Register Set (MRS) command during initialization and may be reprogrammed dynamically without reset.

Does W971GG8SB25I TR support differential DQS operation?

Yes, W971GG8SB25I TR supports differential DQS/DQS operation when enabled via Extended Mode Register (EMR) 1, bit A10 = 0. In this mode, both DQS and DQS pins function as complementary strobes synchronized to read/write data, improving jitter tolerance and timing margin. When disabled (A10 = 1), only single-ended DQS is active and DQS becomes no-connect.

How is on-die termination (ODT) controlled on W971GG8SB25I TR?

ODT on W971GG8SB25I TR is controlled by the dedicated ODT pin (Ball F9), which must be driven HIGH to enable internal termination resistors on DQ and DQS lines. Termination strength (75 Ω or 150 Ω) is set via EMR(1) bits A1–A0. ODT remains active only during READ/WRITE bursts and is automatically disabled during idle or precharge states to minimize power.

What is the purpose of OCD calibration in W971GG8SB25I TR?

OCD (Off-Chip Driver) calibration in W971GG8SB25I TR adjusts the output driver impedance to match the PCB trace characteristic impedance (typically 50 Ω), reducing signal reflections and improving eye diagram quality. Calibration is performed post-initialization using a dedicated sequence involving EMR(1) commands and requires a known-good reference resistor on the board.

Can W971GG8SB25I TR operate in self-refresh mode at +95°C?

Yes, W971GG8SB25I TR supports self-refresh operation across its full industrial temperature range (−40°C to +95°C). At temperatures above +85°C, the device requires doubled refresh frequency (tREFI = 3.9 µs instead of 7.8 µs), achieved by setting A7 = 1 in EMR(2). This ensures data retention integrity without host intervention during thermal stress conditions.