Winbond Electronics Corporation W957D6HBCX7I TR

Overview

W957D6HBCX7I TR from Winbond is a 128Mb x16 asynchronous/burst/synchronous pseudo-static RAM (PSRAM) with address/data multiplexing, 70ns random access time, 133MHz max clock rate, and 54-ball VFBGA package. It serves as a low-power, high-bandwidth memory replacement for SRAM in portable embedded systems requiring burst-mode Flash-compatible interfacing.

For engineers reviewing the W957D6HBCX7I TR datasheet, W957D6HBCX7I TR pinout, W957D6HBCX7I TR application, or W957D6HBCX7I TR equivalent, key selection considerations include its dual-mode bus operation (asynchronous + burst), temperature-compensated refresh (TCR), partial-array refresh (PAR), deep power-down (DPD), and CellularRAM 1.5 compliance.

Technical Context

This PSRAM integrates a DRAM core with SRAM-like interface logic, enabling seamless drop-in replacement for SRAM while delivering higher density and lower standby current. Its dual-register architecture-Bus Configuration Register (BCR) and Refresh Configuration Register (RCR)-enables runtime reconfiguration of burst length (4/8/16/32/continuous), latency mode (fixed/variable), drive strength, WAIT polarity, and refresh behavior.

The device supports three distinct operational modes: asynchronous (ADV#-triggered, CLK static), synchronous burst (CLK-driven, ADV#-latched), and mixed-mode transitions. It implements transparent self-refresh with no controller intervention, and uses on-die temperature sensing to dynamically adjust refresh intervals-reducing standby current up to 50% at lower temperatures.

Key Specifications

Pinout & Package

Package: 54-ball Very Thin Fine-Pitch Ball Grid Array (VFBGA), 8mm × 8mm × 0.6mm, 0.5mm ball pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS66WV12816EBLL-70BLI, W957D6HBCX7I TR reduces system-level power by eliminating external refresh circuitry and enabling dynamic power scaling; compared with W958D6HBGX7I, it offers optimal cost/density balance for 128Mb use cases without over-provisioning memory.

Availability

W957D6HBCX7I TR is available at Aetrix Electronics and suitable for smartphone application processor cache, industrial HMI display buffer, wireless IoT sensor hub, and automotive ADAS preprocessing buffer applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for W957D6HBCX7I TR 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, PSRAM, and audio codecs, with global manufacturing and quality certifications.

The W957D6HBCX7I TR belongs to Winbond's CellularRAM-compliant ADMUX PSRAM product line, designed specifically to bridge the density-power gap between SRAM and DRAM in portable and battery-operated embedded systems.

FAQ

What is the difference between asynchronous and burst mode operation in the W957D6HBCX7I TR?

The W957D6HBCX7I TR supports two primary bus modes controlled by BCR[15]. In asynchronous mode (BCR[15]=1), operations are triggered by ADV#, with CE#, OE#, and WE# defining read/write cycles - no CLK required. In burst mode (BCR[15]=0), CLK synchronizes transfers; addresses are latched on the first rising CLK edge after ADV# goes low, and subsequent data words follow on consecutive clocks. Burst mode enables higher throughput but requires WAIT monitoring in variable-latency reads.

How does the WAIT signal function during burst READ operations in the W957D6HBCX7I TR?

In the W957D6HBCX7I TR, WAIT is an open-drain output that asserts (driven LOW) during burst READs to indicate either a refresh collision or row boundary crossing. During variable-latency reads, the host must monitor WAIT to determine when valid data appears. In fixed-latency mode, WAIT is ignored after initial latency expires. WAIT is High-Z when CE# is HIGH and must be externally pulled up per datasheet recommendations.

Can the W957D6HBCX7I TR operate without an external clock source?

Yes - the W957D6HBCX7I TR operates fully in asynchronous mode without CLK. In this mode, CLK may be tied to VSSQ or VCCQ (per datasheet Note 1). However, burst mode, synchronous timing, and certain low-power features like precise DPD exit timing require CLK to be active. Asynchronous mode retains full functionality including PAR, TCR, and DPD, making it viable for simple microcontroller interfaces.

What is the purpose of the CRE pin on the W957D6HBCX7I TR?

The CRE (Control Register Enable) pin on the W957D6HBCX7I TR enables access to internal configuration registers: Bus Configuration Register (BCR), Refresh Configuration Register (RCR), and Device ID Register (DIDR). When CRE is HIGH, WRITE cycles load BCR or RCR, and READ cycles return register contents instead of memory array data. CRE must be asserted to enter Deep Power-Down (by writing RCR[4]=1) or configure burst parameters.

Does the W957D6HBCX7I TR support partial-array refresh, and how is it configured?

Yes - the W957D6HBCX7I TR supports Partial-Array Refresh (PAR) via bits RCR[2:0] in the Refresh Configuration Register. Values 000–100 select full array, 1/2, 1/4, 1/8, or 1/16 sub-array refresh. PAR reduces refresh current proportionally - e.g., 1/4 array refresh cuts refresh-related current by ~75%. Configuration requires CRE HIGH, CE# LOW, and proper address/data sequencing per the "Configuration register WRITE" timing diagram.