Winbond Electronics Corporation W9412G6JH-4

Overview

W9412G6JH-4 from Winbond Electronics is a 2M × 4 banks × 16-bit DDR SDRAM IC operating at up to 250 MHz with 2.4–2.7 V supply, CL2–CL4 latency support, and SSTL_2 interface - designed for high-bandwidth main memory in embedded computing and industrial control systems requiring DDR500/CL3–CL4 compliance.

For engineers reviewing the W9412G6JH-4 datasheet, W9412G6JH-4 pinout, W9412G6JH-4 application, or W9412G6JH-4 equivalent, key selection factors include tCK = 4 ns (CL=4), tRAS ≥ 40 ns, burst length programmability (2/4/8), differential clock (CLK/CLK̅) timing, and TSOP II 66-pin package compatibility with legacy DDR memory controllers.

Technical Context

This DDR SDRAM implements double-data-rate architecture synchronized to both edges of DQS for read/write data transfers, with DLL-enabled timing calibration and programmable mode register settings for CAS latency, burst length, and addressing mode. It supports bank-interleaved reads across all four internal banks to sustain peak bandwidth.

Command decoding relies on CS, RAS, CAS, and WE inputs sampled on CLK/CLK̅ crossing; write masking uses LDM/UDM per-byte control aligned with DQS edges; and refresh is managed via auto-refresh (tREFI = 15.6 µs) or self-refresh (IDD6 ≤ 2 mA) modes - all compliant with JEDEC DDR SDRAM standard JESD79.

Key Specifications

Pinout & Package

W9412G6JH-4 is housed in a RoHS-compliant, lead-free 66-pin TSOP II (400 mil) package with separate VDD/VDDQ and VSS/VSSQ rails for logic and I/O noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MT46V32M16P-5B:J and IS42S16320B-6TL, W9412G6JH-4 uniquely supports DDR500 operation (250 MHz), programmable CL4, and 2.4–2.7 V supply - making it the only option among the three for industrial applications demanding higher bandwidth and voltage robustness.

Availability

W9412G6JH-4 is available at Aetrix Electronics and suitable for industrial HMI display controllers, network router packet buffers, medical imaging front-end modules, and automotive ADAS camera preprocessors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for W9412G6JH-4 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 NOR/NAND Flash, SRAM, and DRAM products for industrial, automotive, and communications markets.

W9412G6JH-4 belongs to Winbond's DDR SDRAM product line engineered for cost-effective, pin-compatible migration from legacy SDR and early DDR platforms in resource-constrained embedded systems.

FAQ

What is the maximum operating frequency supported by W9412G6JH-4?

W9412G6JH-4 supports a maximum clock frequency of 250 MHz, corresponding to a DDR500 data rate (500 MT/s). This is validated by its -4 speed grade specification, which guarantees tCK = 4 ns minimum clock cycle time under CL4 conditions and 2.4–2.7 V supply. Operation above 250 MHz violates timing specifications and may cause data corruption or command decode failure.

Does W9412G6JH-4 require external VREF, and what is its nominal value?

Yes, W9412G6JH-4 requires an externally supplied VREF reference voltage at Pin 49, with a nominal value of 1.25 V ±1% - mandated by the SSTL_2 interface standard. This reference must remain stable during all operational modes, including self-refresh, and must be decoupled with 0.1 µF ceramic capacitance near the VREF pin to maintain input threshold accuracy.

Can W9412G6JH-4 operate with a 2.5 V ±0.2 V supply like DDR400 SDRAMs?

No - W9412G6JH-4 is specified for DDR500 operation and requires a 2.4 V to 2.7 V supply range. While 2.5 V falls within this window, the ±0.2 V tolerance (2.3–2.7 V) exceeds the lower limit of 2.4 V. Supplying 2.3 V risks violating tCK and setup/hold timing margins; use only regulated 2.4–2.7 V sources with ≤±2% tolerance for reliable W9412G6JH-4 operation.

How many banks does W9412G6JH-4 contain, and how are they accessed?

W9412G6JH-4 contains four independent memory banks (Bank #0 through Bank #3), selected using BA0 and BA1 address pins during activate, read, write, and precharge commands. Bank interleaving allows concurrent row activation across banks, enabling continuous burst transfers without waiting for tRAS to expire - critical for sustaining peak bandwidth in streaming applications.

What is the purpose of the LDM and UDM pins on W9412G6JH-4?

LDM (Pin 20) and UDM (Pin 43) are byte-level write mask signals on W9412G6JH-4: LDM controls masking of DQ0–DQ7 (lower byte), and UDM controls DQ8–DQ15 (upper byte). When asserted high during a write burst, they prevent corresponding data bytes from being written to the memory array - essential for partial-word updates without read-modify-write overhead.