Winbond Electronics Corporation W631GU8KB15I

Overview

W631GU8KB15I from Winbond is a 1G-bit DDR3L SDRAM organized as 16M × 8 banks × 8 bits, operating at 1.35V nominal supply with industrial temperature range (–40°C to +95°C), supporting DDR3L-1333 speed grade (9-9-9 timing), and delivering 1333 Mb/sec/pin data transfer rate for embedded memory subsystems in networking and industrial controllers.

For engineers reviewing the W631GU8KB15I datasheet, W631GU8KB15I pinout, W631GU8KB15I application, or W631GU8KB15I equivalent, this page delivers verified electrical specs, ball mapping, JEDEC-compliant DDR3L timing behavior, industrial-grade thermal validation, and direct substitution guidance against functionally aligned low-voltage SDRAM alternatives.

Technical Context

The W631GU8KB15I implements an 8-bank, 8-bit prefetch architecture synchronized to differential CK/CK# inputs, with DLL-aligned DQS/DQS# strobes for source-synchronous read/write operations. It supports programmable CAS Latency (CL = 6, 7, 8, 9, 10), CAS Write Latency (CWL = 5–7), additive latency (AL = 0, CL−1, CL−2), and on-die termination (ODT) with dynamic Rtt_WR control.

It features ZQ calibration for output driver and ODT impedance tuning using an external 240Ω reference resistor, asynchronous RESET# for power-up initialization, and multi-purpose register (MPR) support for system-level timing calibration via write leveling and predefined bit pattern reads - all compliant with JEDEC JESD79-3F DDR3L specifications.

Key Specifications

Pinout & Package

Packaged in 78-ball WBGA (8 mm × 10.5 mm, RoHS-compliant, lead-free), with ball pitch of 0.8 mm and standard DDR3L signal assignment including differential clocks (CK/CK#), strobes (DQS/DQS#), command/control (CS#/RAS#/CAS#/WE#), address (A0–A13, BA0–BA2), data (DQ0–DQ7), and dedicated ZQ, RESET#, ODT, and VREF pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT41K128M8RH-125:E and IS43TR16128AL-125KBL, the W631GU8KB15I offers optimized cost-performance balance for 1333 Mbps industrial applications, with lower timing margin requirements and proven compatibility in legacy DDR3L-1333 controller implementations - avoiding over-specification where full 1600 Mbps headroom is unnecessary.

Availability

W631GU8KB15I is available at Aetrix Electronics and suitable for networking equipment, industrial PLC controllers, medical imaging subsystems, and video surveillance DVRs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W631GU8KB15I 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 SPI NOR Flash, DDR SDRAM, and mobile DRAM, with global manufacturing and quality certifications.

The W631GU8KB series belongs to Winbond's industrial-grade DDR3L SDRAM product line, designed specifically for embedded applications demanding extended temperature operation, low-voltage efficiency, and JEDEC-compliant reliability in space-constrained, thermally challenging environments.

FAQ

What is the maximum supported CAS Latency for W631GU8KB15I at DDR3L-1333 speed?

The W631GU8KB15I supports CAS Latency settings of CL = 6, 7, 8, 9, and 10 at DDR3L-1333 speed. Per the datasheet Table 4, Sup_CL for the -15/15I speed grade includes 6, (7), 8, 9, 10 - where parentheses indicate optional down-binned support contingent on SPD programming. The W631GU8KB15I achieves tAA min = 13.5 ns at CL=9, matching the 9-9-9 timing bin specification.

Does W631GU8KB15I support both DDR3L and standard DDR3 voltage modes?

Yes, the W631GU8KB15I is backward compatible with 1.5V DDR3 operation. Its VDD/VDDQ supply range is specified as 1.283 V to 1.45 V for DDR3L mode and 1.425 V to 1.575 V for DDR3 mode. Section 11 confirms functional compatibility, though DC characteristics like IDD0/IDD1 differ slightly between modes - the W631GU8KB15I maintains full JEDEC timing compliance in both configurations.

What is the purpose of the ZQ pin on W631GU8KB15I and how must it be connected?

The ZQ pin on W631GU8KB15I serves as the reference terminal for factory-trimmed output driver and on-die termination (ODT) impedance calibration. It must be connected to a single 240Ω ±1% external resistor tied to ground, as specified in Section 8.18 and Table 10.9.4. This connection enables the W631GU8KB15I to perform periodic ZQ calibration commands (ZQCL, ZQCS) to maintain ±10% impedance accuracy across voltage and temperature variations.

Can W631GU8KB15I operate reliably at 95°C case temperature?

Yes, the W631GU8KB15I is rated for –40°C ≤ TCASE ≤ 95°C in its 15I industrial grade variant. At 85°C < TCASE ≤ 95°C, JEDEC requires doubling the refresh rate (tREFI = 3.9 µS instead of 7.8 µS), which the W631GU8KB15I supports via Auto Self Refresh (ASR) mode (MR2[7:6] = 10b) or Manual Self-Refresh with Extended Temperature Range (MR2[7:6] = 10b). This capability is explicitly validated in Section 4 notes and Table 4.

How does the RESET# pin function during power-up for W631GU8KB15I?

The RESET# pin on W631GU8KB15I provides asynchronous initialization: asserting RESET# LOW for ≥200 ns after VDD/VDDQ stabilize initiates the power-up initialization sequence defined in Section 8.2.1. This forces internal registers to default states, clears pending commands, and prepares the DLL and ODT circuits - independent of clock presence. The W631GU8KB15I requires no external reset controller; a simple RC circuit or processor GPIO suffices to meet the timing requirement.