Winbond Electronics Corporation W631GU8NB-15

Overview

W631GU8NB-15 from Winbond is a 1 Gb (128 MB) DDR3L SDRAM organized as 16M × 8 banks × 8 bits, operating at 1.35 V nominal supply with DDR3L-1333 speed grade (9-9-9 CL-tRCD-tRP), supporting industrial temperature range (0°C to 95°C), and designed for memory subsystems in embedded controllers, networking equipment, and industrial HMIs requiring low-voltage, high-density synchronous DRAM.

For engineers reviewing the W631GU8NB-15 datasheet, W631GU8NB-15 pinout, W631GU8NB-15 application, or W631GU8NB-15 equivalent, key selection considerations include its 78-ball VFBGA package, programmable CAS Write Latency (CWL = 5–7), on-die termination (ODT), ZQ calibration support, and backward compatibility with 1.5 V DDR3 systems.

Technical Context

This DDR3L SDRAM implements an 8-bit prefetch architecture with eight internal banks, enabling concurrent bank activation and interleaved access to sustain bandwidth. It uses differential CK/CK# inputs for command/address latching and source-synchronous DQS/DQS# strobes aligned edge-to-read-data and center-to-write-data.

The device supports programmable features including additive latency (AL = 0, CL−1, CL−2), auto-precharge, partial array self-refresh (PASR), dynamic ODT (Rtt_WR), and write leveling for timing calibration. Its asynchronous RESET# pin enables deterministic power-up initialization independent of clock stability.

Key Specifications

Pinout & Package

VFBGA-78 package with 8×10.5 mm² footprint, 1.0 mm profile, and ball pitch of 0.8 mm. Ball layout conforms to JEDEC MO-270DA standard for DDR3L SDRAM.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR3L SDRAM applications.

Compared with MT41K128M8RH-125:E and IS43TR16128B-125KBL, the W631GU8NB-15 uniquely combines x8 interface, PASR, write leveling, and ±1 % ZQ tolerance in a JEDEC-standard 78-ball package-making it optimal for cost-sensitive, thermally constrained industrial systems requiring flexible power management and robust timing calibration.

Availability

W631GU8NB-15 is available at Aetrix Electronics and suitable for industrial HMIs, network edge routers, medical diagnostic terminals, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W631GU8NB-15 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 manufacturer specializing in specialty memory solutions, including NOR/NAND Flash, SRAM, and DRAM products for industrial, automotive, and communications markets.

The W631GU8NB-15 belongs to Winbond's DDR3L SDRAM product line, engineered for low-power, high-reliability embedded systems where voltage scalability, thermal resilience, and JEDEC compliance are mandatory design requirements.

FAQ

What is the maximum operating frequency of the W631GU8NB-15?

The W631GU8NB-15 is rated for DDR3L-1333 operation, with a maximum clock frequency of 667 MHz (1333 MT/s). Its tCK(AVG) specification is 1.5 ns minimum for CL=9/CWL=7 configurations, and it supports stable operation up to this rate under 1.283–1.45 V supply and 0°C to 95°C case temperature conditions. The W631GU8NB-15 does not support higher speed bins such as DDR3L-1600 or DDR3L-1866.

Does the W631GU8NB-15 support both 1.35 V and 1.5 V operation?

Yes, the W631GU8NB-15 is fully backward compatible with standard DDR3 1.5 V systems. It operates within VDD/VDDQ = 1.283 V to 1.45 V for DDR3L mode and accepts 1.5 V ±0.075 V for legacy DDR3 compatibility. Voltage switching between modes is supported per JEDEC specification, and the W631GU8NB-15 maintains full AC/DC parameter compliance across both ranges without reconfiguration.

What package type and ball count does the W631GU8NB-15 use?

The W631GU8NB-15 uses a 78-ball Very Thin Fine-Pitch Ball Grid Array (VFBGA) package measuring 8 mm × 10.5 mm with 0.8 mm ball pitch and 1.0 mm maximum height. This JEDEC MO-270DA-compliant package is lead-free and RoHS-compliant. The W631GU8NB-15's pinout matches industry-standard DDR3L SDRAM layouts, enabling direct PCB footprint reuse across compatible devices.

How does the W631GU8NB-15 implement on-die termination (ODT)?

The W631GU8NB-15 supports both synchronous and dynamic ODT modes. It offers programmable termination impedances (RTT_NOM and RTT_WR) via mode registers MR1 and MR2, with values including 75 Ω, 150 Ω, and 50 Ω. Dynamic ODT (Rtt_WR) activates ODT only during WRITE operations, minimizing power consumption and noise coupling. The W631GU8NB-15 also supports ZQ calibration using an external 240 Ω resistor for ±10 % impedance accuracy.

Is write leveling supported on the W631GU8NB-15?

Yes, the W631GU8NB-15 supports hardware-assisted write leveling through its Multi-Purpose Register (MPR) and dedicated write leveling mode. In this mode, the DRAM outputs a predefined bit pattern on DQ while the controller adjusts DQS delay to center-align strobe edges with write data. This feature is explicitly documented in the W631GU8NB-15 datasheet sections 8.9 and 8.10, and is essential for achieving timing margin in high-speed DDR3L-1333 systems.