Winbond Electronics Corporation

W25X40CLSNIG

A: The W25X40CLSNIG offers a flexible, low‑power architecture. The table below summarises its core specifications: Specification Value Memory Density 4 Mbit (512 Kbyte) [10†L31] Memory Organization 512K × 8 bits (2048 pages × 256 bytes per page) [10†L14-L16] Memory Interface SPI (Serial Peripheral Interface) [8†L4-L5] Max Clock Frequency (fR) 104 MHz [7†L8] Equivalent Dual SPI Rate 208 MHz [10†L21-L23] Supply Voltage (VCC) 2.3V to 3.6V [7†L9] Active Read Current 1 mA (typical) [10†L12-L13] Power‑down Current 1 μA (typical) [10†L13] Page Program Time (Tpp) 800 μs max (256 bytes) [7†L9] Sector Erase (4KB) Fast sector erase [10†L37] Block Erase (64KB) 150 ms max [7†L9-L10] Chip Erase Time Standard chip erase command supported Read Operation Access Time 8 ns max [9†L4-L5] Operating Temperature (Industrial) –40°C to +85°C [10†L41] Endurance 100,000 program/erase cycles minimum [7†L9] Data Retention 20 years minimum [7†L10] Package 8‑pin SOIC (150 mil) [7†L7] RoHS Status Lead‑free / RoHS compliant [12†L5] Moisture Sensitivity Level (MSL) Not publicly specified; typical for SOIC packages [4†L8-L10] Additional features include: Flexible Erase Architecture: Uniform 4KB sectors, 32KB blocks and 64KB blocks [10†L31-L32]. SPI with Single and Dual Outputs: Supports standard SPI (CLK, /CS, DI, DO) and Dual SPI (IO0, IO1) for faster data transfer [10†L32-L34]. Hardware and Software Write Protection: Programmable write protection via /WP pin and status register bits, with top or bottom array control [10†L26-L28]. 64‑bit Unique Serial Number: JEDEC standard manufacturer and device ID, plus a unique serial number for device traceability [10†L28-L30].

A: The device uses a standard 4‑wire Serial Peripheral Interface (SPI) bus. The interface consists of four signals: /CS (Chip Select), CLK (Serial Clock), DI (Serial Data Input), and DO (Serial Data Output) [15†L8-L10]. The device supports both SPI Mode 0 (0,0) and Mode 3 (1,1), ensuring compatibility with the vast majority of microcontrollers [15†L13-L15]. Communication begins when the host drives the /CS pin low [9†L10-L11]. Instructions, addresses and data are shifted in on the DI pin on the rising edge of CLK, while data is shifted out on the DO pin on the falling edge of CLK [15†L11-L13]. For higher throughput, the device supports Dual SPI instructions, which allow the DI and DO pins to become bidirectional I/O pins (IO0 and IO1), transferring data at two or three times the rate of ordinary serial flash devices [15†L19-L26]. A key feature is the /HOLD (Hold) function, which allows the host to pause an ongoing serial communication without resetting the ongoing instruction [15†L26-L32]. This is particularly useful in systems where the SPI bus is shared with other devices: a high‑priority interrupt can pause the flash operation, and programming can resume exactly where it left off once the bus is free again [15†L29-L32]. Additionally, the device includes a Write Protect (/WP) pin that, when held low, disables write operations to the memory array when combined with status register bits [10†L26-L28].

A: The W25X40CLSNIG is engineered for long‑term reliability. Key reliability specifications include: Reliability Parameter Specification Program/Erase Endurance 100,000 cycles (minimum) per sector [7†L9] Data Retention 20 years (minimum) [7†L10] Page Program Time (Tpp) 800 μs (max) for 256‑byte page [7†L9] Block Erase Time (64KB) 150 ms max [7†L9-L10] Operating Temperature (Industrial) –40°C to +85°C [10†L41] Active Read Current 1 mA (typical) [10†L40] Power‑down Current 1 μA (typical) [10†L40] The device's 100,000 program/erase cycles and 20‑year data retention are standard for NOR Flash technology, making it suitable for applications that require occasional firmware updates and long‑term code storage. The device also features software/hardware write protection and write enable latch (WEL) for enhanced data security.

A: The W25X40CLSNIG is well‑suited for embedded systems requiring code and data storage with a simple, low‑pin‑count interface. Typical applications include: Firmware storage – Boot code, BIOS, and application code in embedded systems. Code download and shadowing – Quickly downloading code to RAM upon power‑up [10†L11-L12]. Data logging – Storing sensor data, event logs, and system parameters. Configuration storage – Device settings, calibration constants, and user preferences. Voice and text storage – Audio samples, font data and GUI resources [10†L11-L12]. Industrial control, medical devices, networking equipment and consumer electronics. ⚠️ Important Lifecycle Information: The product lifecycle status for the W25X40CLSNIG is conflicting across distributor databases. Multiple sources list the part as Active [13†L20], with one authoritative distributor (DigiKey) listing it as Active and showing thousands of units in stock [8†L18]. However, some distributor pages explicitly state the part as "该型号已停产！" (This model is discontinued) [4†L4-L5][12†L2-L3], while others list the product lifecycle as Obsolete [4†L15-L16][4†L18-L19][4†L22-L23], indicating that Winbond may have phased out this specific "CL" die revision. The W25X40CLSNIG belongs to the older "CL" series (2.3V–3.6V, 104MHz). Winbond currently offers newer "CLSVIG" (W25X40CLSVIG) variants with extended voltage range [13†L25], and the "W25Q" series (W25Q40, W25Q64, etc.) with Quad SPI support as recommended drop‑in alternatives for new designs. Given the conflicting lifecycle reports, engineers are strongly advised to verify current lifecycle status, availability, and lead times directly with an authorised Winbond distributor (such as DigiKey, LCSC, Mouser) before committing this part to a new high‑volume design. For legacy systems already using the W25X40CLSNIG, remaining inventory may still be available, but for new projects requiring long‑term supply assurance, migrating to the W25Q40 series or using the active W25X40CLSVIG variant is recommended.