Winbond Electronics Corporation W979H2KBVX2I

Overview

W979H2KBVX2I from Winbond is a 512Mb LPDDR2-S4B mobile SDRAM organized as 4 banks × 16M × 16-bit, operating at 1.2V core/VDDQ with 800Mbps/pin data rate (LPDDR2-800), supporting burst lengths of 4/8 and CAS latencies of 3/5 in a 134-ball VFBGA package. It serves as main memory in space-constrained portable devices requiring low-power, high-bandwidth mobile DRAM.

For engineers reviewing the W979H2KBVX2I datasheet, W979H2KBVX2I pinout, W979H2KBVX2I application, or W979H2KBVX2I equivalent, key selection criteria include LPDDR2-800 timing compliance (tRCD = 3, tRP = 3), 134-ball VFBGA mechanical compatibility, partial array self-refresh (PASR) support, ZQ calibration capability, and temperature sensor integration for thermal-aware system design.

Technical Context

This device implements the JEDEC LPDDR2 S4B standard with dual-channel differential clock (CK_t/CK_c) and strobe (DQS_t/DQS_c), HSUL_12 I/O interface, and mode register configuration for burst type, CAS latency, drive strength, and temperature compensation. It supports seamless read/write bursts, auto-precharge, all-bank refresh, and deep power-down modes.

Functional operation relies on command decoding via CA[10:0] address/command bus, bank activation using BA[1:0], and per-bank state management. Calibration is enabled through MR10 (ZQ), MR32/MR40 (DQ pattern), and MR4 (device temperature), with MR16 enabling PASR bank masking for dynamic power optimization.

Key Specifications

Pinout & Package

W979H2KBVX2I uses a 134-ball Very Fine Pitch Ball Grid Array (VFBGA) package measuring 10.5mm × 12.5mm × 0.8mm with 0.5mm ball pitch, optimized for high-density mobile PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LPDDR2 memory applications.

Compared with MT42L128M16D1KJ-107 WT:A and IS42S16160F-6BLI, W979H2KBVX2I delivers LPDDR2-specific advantages-lower 1.2V operation, differential signaling, ZQ calibration, and PASR-in a compact 134-ball VFBGA, making it optimal for new portable designs prioritizing power efficiency and thermal awareness over raw density or legacy compatibility.

Availability

W979H2KBVX2I is available at Aetrix Electronics and suitable for smartphone memory subsystems, tablet system memory, automotive infotainment modules, and industrial handheld terminals requiring stable component supply and industrial temperature grade performance.

Supply support for W979H2KBVX2I 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 mobile DRAM for consumer, industrial, and automotive markets.

W979H2KBVX2I belongs to Winbond's LPDDR2-S4B product line, designed specifically for low-power, high-density mobile applications where JEDEC-compliant differential signaling, fine-grained power management, and thermal-aware operation are critical.

FAQ

What is the package type and ball count for W979H2KBVX2I?

W979H2KBVX2I uses a 134-ball Very Fine Pitch Ball Grid Array (VFBGA) package with 0.5mm ball pitch and 10.5mm × 12.5mm body size. This package is specified in Section 4.1 of the official datasheet and is distinct from the 168-ball WFBGA variant used by related part numbers like W979H6KB. The VFBGA footprint supports high-density mobile PCB layouts while maintaining signal integrity for LPDDR2-800 operation.

Does W979H2KBVX2I support ZQ calibration, and what external component is required?

Yes, W979H2KBVX2I supports ZQ calibration via MR23 and MR24 commands to adjust output driver impedance. It requires an external 240Ω ±1% precision resistor (RZQ) connected between ZQ pin and VSS, as defined in Section 7.4.23 and Table 8.2.6.6 of the datasheet. This calibration ensures stable DQ/DM drive strength across voltage and temperature variations, critical for maintaining timing margins at 800Mbps.

What CAS latency options does W979H2KBVX2I support, and how are they configured?

W979H2KBVX2I supports CAS latency (CL) values of 3 and 5, selected via bits A12/A11 in Mode Register 5 (MR5). CL=3 is used for higher-speed operation with tighter timing (e.g., tRCD = 3 cycles), while CL=5 provides additional setup margin in electrically noisy or thermally stressed conditions. Configuration is performed using the Mode Register Write (MRW) command after power-up initialization, as detailed in Section 7.3.7.

How does the temperature sensor in W979H2KBVX2I function, and where is the data stored?

The temperature sensor in W979H2KBVX2I is a silicon diode-based analog circuit whose voltage output is digitized internally and stored in bits [7:0] of Mode Register 4 (MR4), accessible via Mode Register Read (MRR) command. This value reflects real-time die temperature and is used by the host system to adapt refresh intervals or throttle activity. Section 7.4.20 and Table 7.3.6 confirm its presence and register mapping for W979H2KBVX2I.

Is W979H2KBVX2I compatible with LPDDR2-1066 speed grade, or is it limited to LPDDR2-800?

W979H2KBVX2I is rated for LPDDR2-800 operation only, with maximum data rate of 800Mbps/pin and tCK = 1.25ns (800MHz clock). The datasheet specifies timing parameters exclusively for CL=3/5 at this rate (e.g., tRCD = 3 cycles = 3.75ns), and no 1066Mbps timing tables or validation are provided. Attempting LPDDR2-1066 operation violates AC specifications and risks data corruption or initialization failure.