Winbond Electronics Corporation W25X40CLSSIG TR

Overview

W25X40CLSSIG TR from Winbond is a 4 M-bit (512 KB) serial flash memory IC supporting standard SPI, dual-output SPI, and dual I/O SPI interfaces. It features uniform 4 KB sectors, 32 KB blocks, and 64 KB blocks; operates from 2.3 V to 3.6 V; delivers up to 208 Mbps effective data rate via Fast Read Dual I/O (BBh); and supports true execute-in-place (XIP) operation with Continuous Read Mode. It is used for code storage, firmware boot, and parameter retention in space-constrained embedded systems.

For engineers reviewing the W25X40CLSSIG TR datasheet, W25X40CLSSIG TR pinout, W25X40CLSSIG TR application, or W25X40CLSSIG TR equivalent, key selection considerations include its 8-pin SOIC-150mil package, 104 MHz max SPI clock, hardware /WP and /HOLD pins, 4 KB sector granularity, and JEDEC-compliant manufacturer/device ID (EFh/12h).

Technical Context

The W25X40CLSSIG TR implements a SPI-compatible command interface with support for Modes 0 and 3, enabling interoperability with standard microcontroller SPI peripherals. Its dual I/O mode uses bidirectional IO0 and IO1 pins for simultaneous read/write transfers at up to 104 MHz clock frequency, achieving 208 Mbps throughput - matching parallel flash performance without additional address/data bus lines.

Internally, it integrates a 2048-page (256-byte/page) array organized into 128 × 4 KB sectors, 16 × 32 KB blocks, and 8 × 64 KB blocks. The status register includes non-volatile BP2–BP0 and TB bits for flexible hardware/software write protection, while the /WP and /HOLD pins provide real-time external control over write operations and bus arbitration.

Key Specifications

Pinout & Package

W25X40CLSSIG TR is packaged in an 8-pin SOIC-150mil (package code SN), with gull-wing leads, 1.27 mm pitch, and 3.9 mm × 4.9 mm body size. Pin 1 is marked by a notch or dot; pin numbering follows standard counter-clockwise orientation from the marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T and MX25L4006EM1I-12G, the W25X40CLSSIG TR uniquely combines 104 MHz Dual I/O, Continuous Read Mode, and 4 KB sector erase - delivering superior XIP performance and field-update flexibility in constrained industrial and IoT edge devices.

Availability

W25X40CLSSIG TR is available at Aetrix Electronics and suitable for boot code storage, firmware update partitions, and industrial HMI configuration requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for W25X40CLSSIG 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 global semiconductor company specializing in specialty memory solutions, including serial flash, PSRAM, and code storage products for embedded and industrial markets.

The W25X series was designed specifically for cost-sensitive, space-constrained embedded systems requiring high-speed SPI code execution, robust data retention, and flexible hardware/software write protection - targeting MCU boot, IoT node firmware, and industrial controller applications.

FAQ

What is the maximum SPI clock frequency supported by the W25X40CLSSIG TR?

The W25X40CLSSIG TR supports a maximum SPI clock frequency of 104 MHz in standard and dual I/O modes. When using Fast Read Dual I/O (instruction BBh), this yields an effective data transfer rate of 208 Mbps. This specification is validated across the full −40°C to +85°C operating temperature range and 2.3 V to 3.6 V supply voltage, as confirmed in the AC Electrical Characteristics table of the official Winbond datasheet (Rev F, March 2014).

Does the W25X40CLSSIG TR support true execute-in-place (XIP) operation?

Yes, the W25X40CLSSIG TR supports true XIP via its Continuous Read Mode, which reduces instruction overhead to as few as 16 clock cycles per 24-bit address access. This enables direct CPU instruction fetch from flash without intermediate RAM buffering. The feature is enabled via specific status register bits and requires host SPI controller support for continuous clocking - fully documented in Section 7.1.3 and Figure 22 of the W25X40CL datasheet.

What package type is used for the W25X40CLSSIG TR part number?

The W25X40CLSSIG TR uses an 8-pin SOIC-150mil package (package code SN), with 1.27 mm lead pitch, 3.9 mm × 4.9 mm body dimensions, and RoHS-compliant matte tin lead finish. This matches the "SSIG" suffix definition in Winbond's Ordering Information table (Section 11.1), confirming it is distinct from VSOP, WSON, or PDIP variants of the same base W25X40CL die.

How does hardware write protection work on the W25X40CLSSIG TR?

Hardware write protection on the W25X40CLSSIG TR combines the /WP pin with the non-volatile Status Register Protect (SRP) bit. When SRP = 1 and /WP is driven low, writes to the status register (including block protect bits) are blocked - preventing accidental reconfiguration of protected memory regions. This dual-layer mechanism is detailed in Section 7.2.1 and Table in Section 8.1.6 of the datasheet, and applies independently of software write-enable state.

What is the endurance and data retention specification for the W25X40CLSSIG TR?

The W25X40CLSSIG TR guarantees more than 100,000 program/erase cycles per 4 KB sector and greater than 20 years of data retention at +85°C. These values are specified in Section 2 (Features) and validated per JEDEC JESD22-A117 stress testing methodology. Endurance is measured at typical operating conditions (3.0 V, 25°C), with retention extrapolated from accelerated high-temperature testing per industry standards.