Winbond Electronics Corporation W631GU8NB-11

Overview

W631GU8NB-11 from Winbond Electronics is a 1G-bit DDR3L SDRAM organized as 16M × 8 banks × 8 bits, operating at 1.35 V nominal supply with DDR3L-1866 speed grade (13-13-13 CL/tRCD/tRP), supporting CAS Latency 5–11 and CWL 5–9. It delivers 1866 MT/s data rates in systems requiring low-voltage memory for embedded controllers, industrial HMIs, and network edge devices.

For engineers reviewing the W631GU8NB-11 datasheet, W631GU8NB-11 pinout, W631GU8NB-11 application, or W631GU8NB-11 equivalent, this device requires attention to its VFBGA-78 package, differential CK/CK# and DQS/DQS# timing alignment, ZQ calibration sequence, and industrial-temperature-compatible ODT configuration for signal integrity in high-density PCB layouts.

Technical Context

This DDR3L SDRAM implements an 8-bit prefetch architecture with eight internal banks enabling concurrent access, DLL-based clock-data alignment, and programmable additive latency (AL = 0, CL−1, CL−2) to decouple command bus efficiency from CAS latency. Its asynchronous RESET# pin enables deterministic power-up initialization independent of clock stability.

It supports dynamic on-die termination (Rtt_WR) during writes, multi-purpose register (MPR) readout for system-level timing calibration, and write leveling for per-lane DQS-to-DQ skew compensation-critical for reliable 1866 MT/s operation across temperature and voltage corners.

Key Specifications

Pinout & Package

VFBGA-78 package with 8×10.5 mm² footprint, 1.0 mm thickness, and ball pitch of 0.8 mm. Ball map conforms to JEDEC MO-270AC 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-11 provides unique support for MPR-based system calibration and write leveling within an 8-bit bus, enabling robust 1866 MT/s operation in thermally constrained industrial layouts without requiring controller-level timing guardbanding.

Availability

W631GU8NB-11 is available at Aetrix Electronics and suitable for industrial HMIs, network edge routers, medical imaging terminals, and smart energy gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W631GU8NB-11 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 DRAM products for industrial, automotive, and communications markets.

The W631GU8NB series belongs to Winbond's DDR3L SDRAM product line, designed specifically for cost-sensitive, thermally constrained embedded systems needing JEDEC-compliant low-voltage memory with enhanced calibration and power management features.

FAQ

What is the maximum data rate supported by the W631GU8NB-11?

The W631GU8NB-11 supports a maximum data rate of 1866 MT/s (megatransfers per second), corresponding to a 933 MHz differential clock frequency. This is achieved under DDR3L-1866 speed bin conditions (13-13-13 timing), with validated operation across 0°C to 95°C case temperature and 1.283–1.45 V supply. The W631GU8NB-11 achieves this rate using its 8-bit prefetch architecture and DLL-aligned DQS-to-DQ timing.

Does the W631GU8NB-11 support both 1.35 V and 1.5 V operation?

Yes, the W631GU8NB-11 is fully backward compatible with standard DDR3 1.5 V operation while being optimized for DDR3L 1.35 V. It accepts VDD/VDDQ from 1.283 V to 1.45 V for DDR3L mode and 1.425 V to 1.575 V for DDR3 mode. Voltage switching between modes is supported via controlled sequencing, and all AC/DC specifications remain valid across both ranges. The W631GU8NB-11 maintains identical timing parameters in either mode.

How does write leveling function on the W631GU8NB-11?

Write leveling on the W631GU8NB-11 uses the MPR to output a predefined bit pattern while the memory controller adjusts DQS delay to center-align strobe edges with DQ valid windows. The W631GU8NB-11 responds with feedback via DQ, allowing per-lane skew correction. This process is mandatory before reliable 1866 MT/s writes and is enabled via MR2 bit A1. The W631GU8NB-11 implements full JEDEC-compliant write leveling with dedicated MPR address mapping.

What package type and ball count does the W631GU8NB-11 use?

The W631GU8NB-11 uses a VFBGA-78 package: very thin fine-pitch ball grid array with 78 solder balls arranged in an 8 mm × 10.5 mm body, 1.0 mm maximum height, and 0.8 mm ball pitch. It complies with JEDEC MO-270AC and is RoHS-compliant with lead-free terminations. The W631GU8NB-11's ball map matches industry-standard DDR3L SDRAM layouts for drop-in compatibility with existing 78-ball footprints.

Can the W631GU8NB-11 operate in Partial Array Self Refresh (PASR) mode?

Yes, the W631GU8NB-11 supports Partial Array Self Refresh (PASR) as defined in MR2. By setting MR2[A5:A3] to select ¼, ½, or ¾ of total banks for refresh, the W631GU8NB-11 reduces self-refresh current (IDD6) proportionally - down to ~5 mA in quarter-array mode. This feature is especially valuable in battery-backed or thermally limited applications where full-array refresh would exceed thermal or power budgets. The W631GU8NB-11 implements PASR per JEDEC JESD79-3F specification.