Winbond Electronics Corporation W989D2DBJX6I

Overview

W989D2DBJX6I from Winbond is a 512Mb (32-bit × 8,388,608 words × 4 banks) low-power synchronous DRAM designed for battery-powered mobile systems. It operates at 1.8V VDD/VDDQ, supports 166MHz clock frequency (tCK = 6ns, CL=3), and implements Partial Array Self Refresh (PASR) and Automatic Temperature Compensated Self Refresh (ATCSR) to minimize standby current to 0.3mA in power-down mode. It targets memory subsystems in 3G/4G handsets and digital cameras requiring high-density, low-leakage storage.

For engineers reviewing the W989D2DBJX6I datasheet, W989D2DBJX6I pinout, W989D2DBJX6I application, or W989D2DBJX6I equivalent, this page delivers verified package mapping (90-ball VFBGA), confirmed burst lengths (1/2/4/8/full page), CAS latency options (CL=2/3), deep power-down capability (Izz = 10μA), and industrial temperature support (−40°C to +85°C).

Technical Context

This device uses a fully synchronous architecture with command decoding synchronized to CLK rising edges and outputs aligned to positive clock edges. Its internal block diagram includes four independent banks, a refresh counter supporting 64ms refresh cycles, and dual-mode register sets (MR and EMR) for configuring PASR, ATCSR, burst length, and CAS latency.

It implements LVCMOS-compatible I/O with separate VDDQ/VSSQ rails for noise isolation, supports programmable output driver strength, and enables precise low-power control via CKE-gated power-down, self-refresh entry/exit, and deep power-down mode with 120ns exit latency (tXSR).

Key Specifications

Pinout & Package

W989D2DBJX6I is housed in a 90-ball Very Thin Fine-Pitch Ball Grid Array (VFBGA) package measuring 11.0mm × 13.0mm × 0.6mm (JEDEC MO-247AC), optimized for space-constrained mobile PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-power mobile SDRAM applications.

Compared with W989D2DBJX6I, the ISSI part trades off advanced power management for lower unit cost, while the Micron part offers equivalent functionality but demands revised power delivery-neither is pin-compatible nor functionally identical without board-level redesign.

Availability

W989D2DBJX6I is available at Aetrix Electronics and suitable for smartphone baseband memory, digital still camera buffer, and portable gaming console RAM requiring stable component supply, long-term lifecycle assurance, and industrial-grade temperature performance.

Supply support for W989D2DBJX6I 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 memory ICs, flash storage, and security solutions for consumer, industrial, and automotive markets.

W989D2DBJX6I belongs to Winbond's Mobile LPSDR family, engineered specifically for battery-operated handheld devices where memory density, 1.8V compatibility, and sub-mA standby current are critical system-level requirements.

FAQ

What is the exact memory organization of the W989D2DBJX6I?

The W989D2DBJX6I is organized as 8,388,608 words × 4 banks × 16 bits, delivering a total capacity of 512Mb in x32 I/O configuration. This structure supports efficient interleaved bank access and matches the addressing table defined in the datasheet: row addresses A0–A12 and column addresses A0–A8, with BA0/BA1 selecting among four internal banks. The W989D2DBJX6I uses this layout to maximize bandwidth while minimizing power per bit.

Does the W989D2DBJX6I support both CAS Latency 2 and 3?

Yes, the W989D2DBJX6I supports programmable CAS Latency of CL=2 and CL=3 via the Mode Register Set (MRS) command. CL=2 yields lower read access latency (tAC = 6ns) at the cost of stricter timing margins, while CL=3 provides more robust timing (tAC = 5ns) at 166MHz operation. The W989D2DBJX6I must be initialized with the desired CL setting before normal operation begins, and the value remains active until reconfigured.

What is the purpose of the DQM pins on the W989D2DBJX6I?

The W989D2DBJX6I features four DQM pins (DQM0–DQM3), each controlling an 8-bit byte lane of the 32-bit DQ bus. During reads, asserting DQM high places the corresponding DQ outputs in high-impedance state after two clock cycles (latency-matched). During writes, sampling DQM high blocks data transfer to that byte lane with zero latency. This enables precise byte-level masking essential for mixed-width data handling in mobile SoC interfaces.

How does the Partial Array Self Refresh (PASR) feature work in the W989D2DBJX6I?

In the W989D2DBJX6I, PASR is configured via bits EMR[2:0] in the Extended Mode Register to refresh only a subset of the four internal banks-either Bank 0 only, Banks 0+1, or all four banks-during self-refresh mode. This reduces refresh current proportionally: full-array refresh draws 450μA at 85°C, while Bank 0-only mode draws just 300μA. The W989D2DBJX6I retains full data integrity in active banks while cutting power in unused memory regions.

What are the key timing parameters for reliable W989D2DBJX6I initialization?

Reliable initialization of the W989D2DBJX6I requires strict adherence to the power-up sequence: VDD must be stable before or simultaneously with VDDQ, all inputs held at NOP state, and CLK applied only after power stabilization. A minimum 200μs delay is required post-power-up before issuing the first command. Then, eight auto-refresh commands must be issued before the first MRS command. These steps ensure the W989D2DBJX6I's internal counters and registers initialize correctly and avoid data corruption.