Winbond Electronics Corporation W634GU8QB-09

Overview

W634GU8QB-09 from Winbond is a 4Gb (64M × 8) DDR3L SDRAM organized across 8 internal banks, operating at 1.35V nominal supply with DDR3L-2133 speed grade (14-14-14 CL-tRCD-tRP), supporting up to 2133 MT/s data rates and designed for memory subsystems in industrial embedded controllers, network edge devices, and automotive infotainment head units.

For engineers reviewing the W634GU8QB-09 datasheet, W634GU8QB-09 pinout, W634GU8QB-09 application, or W634GU8QB-09 equivalent, key selection considerations include its -09 speed bin's 1066 MHz clock frequency, 1.35V VDD/VDDQ operation with 1.5V backward compatibility, CAS latency support up to CL=14, and industrial temperature range (0°C to 95°C).

Technical Context

This DDR3L SDRAM implements an 8-bit prefetch architecture synchronized to differential CK/CK# inputs, with DLL-aligned DQ/DQS timing and bi-directional differential strobes that are edge-aligned on reads and center-aligned on writes. It supports programmable additive latency (AL = 0, CL−1, CL−2), posted CAS, and auto-precharge for burst operations.

The device integrates ZQ calibration for output driver and ODT impedance tuning, dynamic ODT (Rtt_WR) with selectable termination values, and multi-purpose register (MPR) readout for system-level timing calibration. Its asynchronous RESET# pin enables deterministic power-up initialization and runtime reset independent of clock state.

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-270DA standard for DDR3L SDRAM.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W634GU8QB-09, both alternatives offer DDR3L compliance but lack its 4Gb density, 2133 MT/s capability, and full JEDEC calibration suite (MPR + write leveling + ZQ), making them suitable only for less demanding memory subsystems.

Availability

W634GU8QB-09 is available at Aetrix Electronics and suitable for industrial PLC memory buffers, automotive infotainment RAM, and network edge router cache applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W634GU8QB-09 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 W634GU8QB-09 belongs to Winbond's DDR3L SDRAM product line, engineered for high-reliability embedded systems requiring low-voltage operation, extended temperature tolerance, and JEDEC-compliant calibration features.

FAQ

What is the maximum clock frequency supported by the W634GU8QB-09?

The W634GU8QB-09 supports a maximum clock frequency of 1066 MHz, enabling a data transfer rate of 2133 MT/s (DDR3L-2133). This is validated under the -09 speed grade with CL-tRCD-tRP = 14-14-14 timing and VDD/VDDQ = 1.283 V to 1.45 V at 0°C to 95°C case temperature. The W634GU8QB-09 achieves this performance while maintaining full JEDEC DDR3L compliance.

Does the W634GU8QB-09 support 1.5V operation?

Yes, the W634GU8QB-09 is backward compatible with 1.5V DDR3 operation per JEDEC JESD79-3F specification. It accepts VDD/VDDQ = 1.5V ± 0.075 V and maintains functional timing and electrical behavior, allowing seamless integration into legacy 1.5V memory subsystems without redesign. The W634GU8QB-09 retains all DDR3L features-including low-power modes-even at 1.5V.

How does the W634GU8QB-09 handle power-up initialization?

The W634GU8QB-09 uses an asynchronous RESET# pin to initiate a deterministic power-up initialization sequence. When RESET# is asserted low after VDD/VDDQ stabilize, the device executes internal DLL reset, ZQ calibration, and mode register programming before entering idle state. This ensures repeatable timing alignment without requiring external clock conditioning. The W634GU8QB-09 guarantees initialization completion within 200 µs of RESET# deassertion.

What calibration features does the W634GU8QB-09 provide for system-level timing margining?

The W634GU8QB-09 provides three hardware-calibration features: ZQ calibration for output driver and ODT impedance tuning, write leveling for DQS-to-CK delay compensation, and Multi-Purpose Register (MPR) readout of a predefined 128-bit pattern for eye diagram analysis. These features are fully JEDEC-compliant and require no firmware intervention. The W634GU8QB-09 supports all three simultaneously during system bring-up.

Is the W634GU8QB-09 pin-compatible with other Winbond DDR3L SDRAMs?

The W634GU8QB-09 uses a standardized VFBGA-78 package conforming to JEDEC MO-270DA, and its ball assignment matches Winbond's W63xGU8xx family (e.g., W632GU8QB-12). Pin functions-including A0–A14, BA0–BA2, DQ0–DQ7, DQS/DQS#, and RESET#-are identical across speed grades. However, timing parameters and supported CL/CWL values differ; the W634GU8QB-09 must be configured per its -09 speed bin specifications.