Winbond Electronics Corporation W631GU8NB-11 TR

Overview

W631GU8NB-11 TR 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-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 industrial computing, network edge devices, and embedded controllers.

For engineers reviewing the W631GU8NB-11 TR datasheet, W631GU8NB-11 TR pinout, W631GU8NB-11 TR application, or W631GU8NB-11 TR equivalent, key selection criteria include its VFBGA-78 package, 1.35 V operation with 1.5 V backward compatibility, programmable ODT and ZQ calibration, DLL-aligned DQS/DQ timing, and industrial temperature support up to 95°C.

Technical Context

This DDR3L SDRAM implements an 8-bit prefetch architecture with eight internal banks enabling concurrent access, and uses differential CK/CK# inputs synchronized at the crossing point for command/address latching. Its bi-directional DQS/DQS# strobes are edge-aligned on reads and center-aligned on writes, with DLL alignment to CK for precise timing control.

The device supports full JEDEC DDR3L features including posted CAS with additive latency (AL = 0, CL−1, CL−2), auto-precharge, dynamic ODT (Rtt_WR), partial array self-refresh (PASR), and write leveling for system-level timing calibration. Mode registers MR0–MR3 configure CAS latency, CWL, ODT settings, PASR, ASR, and MPR functionality.

Key Specifications

Pinout & Package

VFBGA-78 package (8 mm × 10.5 mm, 1.0 mm height) with 78 solder balls arranged in 8×10 array plus 2 dummy balls (B1, H10). Ball pitch is 0.8 mm. Compliant with JEDEC MO-270AC standard.

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 W631GU8NB-11 TR offers unique value in industrial thermal resilience (95°C case), integrated PASR/ASR for ultra-low-power standby, and full CL/CWL programmability across 5–11/5–9 ranges - enabling fine-grained optimization of latency, power, and signal integrity in constrained embedded platforms.

Availability

W631GU8NB-11 TR is available at Aetrix Electronics and suitable for industrial automation, network infrastructure, and medical imaging systems requiring stable component supply, long-term lifecycle assurance, and guaranteed 0–95°C operation.

Supply support for W631GU8NB-11 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 manufacturer specializing in specialty memory solutions, including SPI NOR Flash, DDR SDRAM, and mobile LPDDR products for industrial, automotive, and communications markets.

The W631GU8NB product line delivers JEDEC-compliant DDR3L SDRAM optimized for industrial temperature operation, low-voltage efficiency, and robust signal integrity features such as write leveling, dynamic ODT, and ZQ calibration - targeting embedded systems with stringent power, thermal, and reliability requirements.

FAQ

What is the maximum supported CAS Latency for W631GU8NB-11 TR at DDR3L-1866 speed?

The W631GU8NB-11 TR supports CAS Latency values of 5, 6, 7, 8, 9, 10, and 11 at DDR3L-1866 speed. CL = 11 is the highest setting validated for this speed grade, corresponding to a tAA of 13.91 ns and requiring tCK(AVG) < 2.5 ns. This enables design flexibility for latency-critical versus timing-margin-critical applications while maintaining full JEDEC compliance.

Does W631GU8NB-11 TR support 1.5 V operation like standard DDR3?

Yes, W631GU8NB-11 TR is backward compatible with 1.5 V DDR3 operation (VDD/VDDQ = 1.5 V ± 0.075 V), as confirmed in Section 11 of the datasheet. However, it must be initialized and operated in DDR3L mode (1.35 V) unless the host controller explicitly configures for 1.5 V timing and voltage settings - and JEDEC AC parameters are only guaranteed at 1.35 V.

How does the ZQ calibration function in W631GU8NB-11 TR?

W631GU8NB-11 TR performs ZQ calibration using an external 240 Ω ±1 % resistor connected between ZQ pin and VSS. The calibration adjusts internal output driver strength and ODT impedances to compensate for process, voltage, and temperature variations. It can be triggered manually via MRS or automatically during power-up, and is required before high-speed operation to meet tDQSS and tWPRE specifications.

What is the purpose of the RESET# pin on W631GU8NB-11 TR?

The RESET# pin on W631GU8NB-11 TR provides asynchronous, active-low initialization control. It forces the device into a known state during power-up and enables safe reinitialization without cycling power. When asserted, it resets internal registers, terminates all operations, and clears the DLL - essential for recovery after brown-out or system-level fault conditions in industrial environments.

Can W631GU8NB-11 TR operate in DLL-off mode, and when is it used?

Yes, W631GU8NB-11 TR supports DLL-off mode, which disables the delay-locked loop to reduce power and eliminate DLL-related jitter. It is used during low-power states (e.g., precharge power-down) or when system timing margins allow direct DQS-to-CK alignment. Entry/exit requires strict sequencing per Section 8.6 of the datasheet to avoid metastability.