Winbond Electronics Corporation W631GU8MB11I

Overview

W631GU8MB11I from Winbond is a 1G-bit DDR3L SDRAM organized as 16M × 8 banks × 8 bits, operating at 1.35 V nominal supply with industrial temperature range (–40°C to +95°C). It supports DDR3L-1866 speed grade (13-13-13 CL-tRCD-tRP), delivers 1866 MT/s data rates, and features eight internal banks, 8-bit prefetch, and programmable CAS latency (CL = 5–13) for embedded computing and industrial control memory subsystems.

For engineers reviewing the W631GU8MB11I datasheet, W631GU8MB11I pinout, W631GU8MB11I application, or W631GU8MB11I equivalent, this device requires attention to its VFBGA-78 package layout, differential clock (CK/CK#) and strobe (DQS/DQS#) timing alignment, ZQ calibration sequence, and industrial-grade thermal derating for sustained operation in fanless edge controllers and programmable logic interfaces.

Technical Context

This DDR3L SDRAM implements a source-synchronous interface synchronized to differential CK/CK# inputs, with all commands latched on CK rising edge and data referenced to both edges of DQS/DQS#. Its DLL aligns DQ and DQS transitions to CK, enabling precise timing at 1866 MT/s while supporting posted CAS, additive latency (AL = 0, CL−1, CL−2), and dynamic ODT for signal integrity.

The device supports full JEDEC-compliant power management modes including Precharge Power Down, Active Power Down, Self-Refresh, Auto Self-Refresh (ASR), and Partial Array Self Refresh (PASR). It integrates ZQ calibration using an external 240 Ω resistor and provides asynchronous RESET# for deterministic initialization under varying power ramp conditions.

Key Specifications

Pinout & Package

VFBGA-78 package (8 mm × 10.5 mm, 1.0 mm thickness) with 78 solder balls arranged in 8×10 array plus 2 dummy balls; RoHS-compliant, lead-free finish; ball pitch = 0.8 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS43TR16128B-125KBL, W631GU8MB11I offers lower PCB routing complexity and reduced power per byte; compared with MT41K128M8RH-125:E, it provides identical industrial temperature support but distinct ODT configuration granularity and reset initialization behavior.

Availability

W631GU8MB11I is available at Aetrix Electronics and suitable for industrial automation, medical imaging, and network infrastructure applications requiring stable component supply, long-term lifecycle assurance, and guaranteed industrial temperature performance.

Supply support for W631GU8MB11I 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 W631GU8MB series belongs to Winbond's industrial-grade DDR3L SDRAM product line, designed specifically for applications demanding extended temperature operation, low-voltage efficiency, and JEDEC-compliant reliability in harsh environments.

FAQ

What is the maximum supported CAS latency for W631GU8MB11I at DDR3L-1866 speed?

W631GU8MB11I supports CAS latency (CL) values of 5, 6, 8, 10, and 13 at DDR3L-1866 speed. CL = 13 corresponds to the 13-13-13 timing bin specified in the datasheet and is validated for stable operation across the full –40°C to +95°C temperature range. CL = 7 and CL = 9 are not supported for this speed grade per the Sup_CL table in Section 4.

Does W631GU8MB11I require external termination resistors on DQ/DQS lines?

No, W631GU8MB11I integrates programmable on-die termination (ODT) for DQ, DQS/DQS#, and DM signals. External termination is unnecessary when ODT is enabled via MR1/MR2; however, proper ZQ calibration using a 240 Ω ±1% resistor to VSS is mandatory to set accurate ODT and driver impedances for signal integrity at 1866 MT/s.

How does W631GU8MB11I handle refresh at 95°C case temperature?

At TCASE = 95°C, W631GU8MB11I requires doubled refresh frequency (tREFI = 3.9 µS instead of 7.8 µS) to maintain data retention. This is achieved either by enabling Auto Self-Refresh (ASR) via MR2[7:6] = 10b or by entering Manual Self-Refresh mode with MR2[7:6] = 01b - both methods are fully supported and documented in Section 8.3.3.3 of the datasheet.

Can W631GU8MB11I operate at 1.5 V like standard DDR3?

Yes, W631GU8MB11I is backward compatible with 1.5 V DDR3 operation per Section 11. It supports VDD/VDDQ = 1.5 V ± 0.075 V and retains full functionality including timing parameters and command set. However, DDR3L-specific features such as lower IDD currents and optimized 1.35 V AC characteristics are only guaranteed at the 1.35 V nominal supply.

What is the purpose of the Multi-Purpose Register (MPR) in W631GU8MB11I?

The MPR in W631GU8MB11I outputs a fixed 128-bit pattern (0x00000000 repeated) during MPR read mode, enabling system-level timing margin testing without accessing actual memory contents. It is used in conjunction with write leveling and read training to validate DQS-to-DQ timing alignment and signal integrity across all 8 data bits in the W631GU8MB11I interface.