Winbond Electronics Corporation W956D8MBYA5I

Overview

W956D8MBYA5I from Winbond Electronics is a 64Mb HyperRAM device operating at 1.8V with an 8-bit DDR HyperBus interface, supporting up to 200MHz clock frequency (400 MT/s), 24-ball TFBGA package, and industrial temperature range (−40°C to +85°C). It serves as high-speed external memory for microcontrollers and application processors in graphics-intensive embedded systems requiring low-pin-count, high-bandwidth memory expansion.

For engineers reviewing the W956D8MBYA5I datasheet, W956D8MBYA5I pinout, W956D8MBYA5I application, or W956D8MBYA5I equivalent, key selection considerations include configurable burst modes (wrapped/linear/hybrid), dual-clock support (single-ended CK or differential CK/CK#), RWDS-based latency signaling and data masking, partial array refresh capability, and deep power-down mode for ultra-low standby current.

Technical Context

The W956D8MBYA5I implements a DDR HyperBus interface with command/address/data multiplexed on DQ[7:0], using CK/CK# (or CK-only) for timing capture. Transactions begin with CS# assertion and six-byte CA transfer over three clock cycles, where CA[47] defines R/W#, CA[46] selects memory/register space, and CA[45] sets burst type.

It supports two distinct latency mechanisms: initial access latency (tACC) configured via Configuration Register 0, and optional additional latency signaled dynamically by RWDS output during CA phase. RWDS operates bidirectionally - as read data strobe (edge-aligned), write data mask (input), and refresh-latency indicator (output).

Key Specifications

Pinout & Package

W956D8MBYA5I uses a 24-ball TFBGA package (5 mm × 5 mm, 0.8 mm pitch) with ball-down mounting. Pin functions are defined per JEDEC MO-270DA standard and validated in Winbond's official ball assignment diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W956D8MBYA6I and W956A8MBYA5I, the W956D8MBYA5I uniquely delivers 200MHz DDR performance at 1.8V in industrial temperature grade - making it the optimal choice for new 1.8V embedded designs demanding maximum HyperBus bandwidth without voltage translation or derating.

Availability

W956D8MBYA5I is available at Aetrix Electronics and suitable for industrial HMI displays, automotive digital clusters, and edge AI inference accelerators requiring stable component supply, long-term lifecycle assurance, and guaranteed traceability.

Supply support for W956D8MBYA5I 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/NAND Flash, RAM, and interface-optimized memories like HyperRAM.

The W956D8MBYA5I belongs to Winbond's HyperRAM family - designed specifically to replace parallel SRAM and low-density SDRAM in resource-constrained embedded systems needing high bandwidth with minimal pin count and simplified layout.

FAQ

What is the maximum data throughput achievable with W956D8MBYA5I?

The W956D8MBYA5I achieves up to 400 MB/s sustained read throughput in linear burst mode at 200MHz DDR clock (1 byte × 2 edges × 200 MHz). This assumes continuous reads with no CS# de-assertion between bursts and proper host timing alignment to RWDS. Write throughput matches read under identical conditions, though write masking via RWDS may reduce effective bandwidth in byte-aligned scenarios.

Does W956D8MBYA5I support both differential and single-ended clocking?

Yes, W956D8MBYA5I supports both differential (CK/CK#) and single-ended (CK only) clocking modes. CK# is internally ignored when used in single-ended mode, and the device does not require CK# to be terminated or driven. The clock need not be free-running - it starts only during active transactions, reducing EMI and dynamic power consumption.

How does RWDS function during read versus write operations in W956D8MBYA5I?

In W956D8MBYA5I, RWDS serves three distinct roles: (1) During CA phase, it outputs high/low to indicate required refresh latency; (2) During read data transfer, it acts as an edge-aligned read data strobe synchronized to DQ transitions; (3) During write data transfer, it functions as a byte-level mask input - high masks the corresponding byte, low enables write. This eliminates need for separate control lines and simplifies timing closure.

What package and footprint does W956D8MBYA5I use?

W956D8MBYA5I uses a 24-ball TFBGA package (5 mm × 5 mm, 0.8 mm pitch) with ball-down orientation. Its footprint matches JEDEC MO-270DA, and the pinout is fixed across the W956D8MBYA/W956A8MBYA family. PCB layout requires dedicated VCC/VCCQ decoupling, controlled-impedance DQ and CK traces, and strict adherence to Winbond's recommended pad geometry and solder mask clearance.

Can W956D8MBYA5I operate in deep power-down mode while retaining data?

Yes, W956D8MBYA5I retains full memory contents in Deep Power Down mode, drawing less than 2 µA typical ICC. Exit time from Deep Power Down is under 5 µs, and the device automatically reinitializes its internal state upon wake-up. No external refresh or host intervention is required before resuming normal operation, making it ideal for battery-backed or energy-harvesting applications.