Winbond Electronics Corporation W631GU8NB11I

Overview

W631GU8NB11I from Winbond is a 1G-bit DDR3L SDRAM organized as 16M × 8 banks × 8 bits, operating at 1.35V nominal supply with industrial temperature support (−40°C to +95°C), compliant with DDR3L-1866 (13-13-13) timing, and packaged in a lead-free 78-ball VFBGA (8 mm × 10.5 mm). It delivers high-speed memory buffering for embedded controllers and networking SoCs requiring low-voltage, high-density DRAM with robust refresh management.

For engineers reviewing the W631GU8NB11I datasheet, W631GU8NB11I pinout, W631GU8NB11I application, or W631GU8NB11I equivalent, key selection criteria include CAS Latency support (CL = 5–13), programmable CWL (5–9), ZQ calibration capability, on-die termination (RTT_NOM/RTT_WR), and industrial-grade thermal reliability up to 95°C case temperature.

Technical Context

This DDR3L SDRAM implements an 8-bit prefetch architecture with eight internal banks enabling concurrent access, DLL-aligned DQ/DQS timing, and source-synchronous differential strobe I/O (DQS/DQS#). It supports posted CAS with additive latency (AL = 0, CL−1, CL−2), auto-precharge, and multi-mode refresh including ASR and PASR.

Control logic operates synchronously with differential CK/CK# inputs latched at the crossing point; all commands are registered on the rising edge of CK. The device supports write leveling, MPR-based system calibration, and dynamic ODT switching during write bursts to maintain signal integrity across varying load conditions.

Key Specifications

Pinout & Package

Package: 78-ball VFBGA (8 mm × 10.5 mm, 1.0 mm thickness), RoHS-compliant, window-type BGA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS43TR16128B-125KBL and MT41K128M8RH-125:E, the W631GU8NB11I offers identical DDR3L-1866 performance in a compact 78-ball VFBGA, making it optimal for space-constrained industrial controllers where 8-bit bus width and proven thermal reliability are prioritized over density or automotive certification.

Availability

W631GU8NB11I is available at Aetrix Electronics and suitable for industrial HMI controllers, network edge routers, medical imaging modules, and smart energy gateways requiring stable component supply with guaranteed long-term availability and full industrial temperature support.

Supply support for W631GU8NB11I 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 industrial-grade DDR3L SDRAM product line, designed specifically for embedded systems demanding low-voltage operation, extended temperature resilience, and JEDEC-compliant timing stability in harsh environments.

FAQ

What is the maximum clock frequency supported by the W631GU8NB11I?

The W631GU8NB11I supports a maximum clock frequency of 933 MHz, corresponding to DDR3L-1866 operation (13-13-13 timing). This is confirmed in the datasheet's Key Parameters table and applies under industrial temperature conditions (−40°C to +95°C) with VDD/VDDQ = 1.283 V to 1.45 V. The W631GU8NB11I achieves this using programmable CAS Latency and CWL settings aligned to its speed bin.

Does the W631GU8NB11I support backward compatibility with standard 1.5 V DDR3 systems?

Yes, the W631GU8NB11I supports backward compatibility with 1.5 V DDR3 systems. Its VDD/VDDQ supply range extends to 1.5 V ± 75 mV, and it maintains functional compatibility with DDR3 command sets and timing parameters when operated at that voltage. This allows seamless integration into legacy 1.5 V platforms without hardware modification, though DDR3L-specific features like lower IDD currents are only realized at 1.35 V.

How does the W631GU8NB11I handle refresh at elevated temperatures?

At case temperatures above 85°C, the W631GU8NB11I requires doubled auto-refresh frequency (tREFI = 3.9 µS instead of 7.8 µS) to maintain data retention. This is enforced via MR2 bit A7 (ASR enable) or manual entry into Self-Refresh mode with Extended Temperature Range (MR2 A6 = 0, A7 = 1). The W631GU8NB11I's industrial rating up to 95°C mandates this behavior, and the device supports both Auto Self-Refresh (ASR) and Partial Array Self-Refresh (PASR) to manage power under thermal stress.

What is the purpose of the ZQ pin on the W631GU8NB11I?

The ZQ pin on the W631GU8NB11I connects to an external 240 Ω ±1 % precision resistor to ground and enables on-die calibration of output driver strength and on-die termination (ODT) impedances. This calibration compensates for process, voltage, and temperature variations, ensuring consistent signal integrity for DQ, DQS, and DM signals. The W631GU8NB11I performs ZQ calibration at power-up and supports periodic recalibration during operation.

Can the W631GU8NB11I operate with different CAS Latency and CAS Write Latency settings simultaneously?

Yes, the W631GU8NB11I supports independent programming of CAS Latency (CL) and CAS Write Latency (CWL) via Mode Registers MR0 and MR2. CL determines read timing (RL = AL + CL), while CWL governs write timing (WL = AL + CWL). The W631GU8NB11I allows CL = 5–13 and CWL = 5–9, with valid combinations constrained by speed grade - e.g., at DDR3L-1866, CL = 13 pairs with CWL = 9, enabling fine-grained optimization of read/write timing margins.