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Microchip Technology AT25FS040N-SH27-B
- Part No.:
- AT25FS040N-SH27-B
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT25FS040N-SH27-B.pdf
- Description:
- IC FLASH 4MBIT SPI 50MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,218
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Product details
Overview
AT25FS040N-SH27-B from Microchip Technology is a 4 Mbit (524,288 × 8) serial SPI Flash memory IC optimized for low-voltage industrial applications. It operates from 2.7V to 3.6V, supports SPI Modes 0 and 3 at up to 50 MHz, features hardware/software write protection, and delivers 30 µs/byte typical program time with 10,000 write cycles endurance.
For engineers reviewing the AT25FS040N-SH27-B datasheet, AT25FS040N-SH27-B pinout, AT25FS040N-SH27-B application, or AT25FS040N-SH27-B equivalent, this page provides verified technical context, JEDEC SOIC package mapping, sector/block/page architecture details, and real-world use-value for embedded firmware storage, boot code retention, and configuration data logging in space-constrained designs.
Technical Context
The AT25FS040N-SH27-B implements a slave-only SPI interface with dedicated SI/SO pins, CS-controlled selection, and HOLD/ WP pins for suspend and hardware write lockout. Its internal architecture comprises eight uniform 64 Kbyte blocks, each containing sixteen 4 Kbyte sectors, and each sector subdivided into sixteen 256-byte pages - enabling granular erase and program operations without disturbing adjacent data.
All write cycles (program, sector erase, block erase, chip erase, status register update) are self-timed and require prior WREN instruction activation. The device integrates Power-On Reset (POR) circuitry (~1.8 V threshold), input/output capacitance under 8 pF, and supports JEDEC-standard RDID (1Fh/66h/04h) for automated identification in production programming systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4,194,304 bits (524,288 × 8), sufficient for full bootloader + firmware image in compact MCU systems |
| Supply Voltage Range | 2.7 V to 3.6 V - compatible with 3.3 V logic rails and battery-backed industrial power domains |
| Max Clock Frequency | 50 MHz - enables high-throughput firmware updates and fast read access during boot |
| Program Time | 30 µs/byte typical - allows sub-8 ms full-page (256 B) programming, critical for field OTA updates |
| Erase Granularity | Sector (4 KB), Block (64 KB), Chip - supports partial firmware patching without full reflash |
| Endurance | 10,000 write cycles - validated for frequent configuration logging in data acquisition nodes |
| Operating Temperature | –40°C to +85°C - qualified for uncontrolled industrial environments including factory automation controllers |
Pinout & Package
AT25FS040N-SH27-B is packaged in an 8-lead JEDEC-standard 150 mil SOIC (package code 8S1), lead-free/halogen-free with NiPdAu finish, suitable for reflow soldering and long-term reliability in industrial PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; must follow VCC monotonically during power-up/down to prevent spurious writes |
| SCK | Serial Clock Input | Master-generated clock; timing-critical path with 9 ns min high/low times at 50 MHz operation |
| SI | Serial Data Input | Receives opcodes, addresses, and data; MSB-first, requires 5 ns setup/hold relative to SCK |
| SO | Serial Data Output | Drives read data and status bits; output valid within 9 ns of SCK edge, high-Z when deselected |
| GND | Ground Reference | Common return for VCC, signals, and internal charge pumps; must be low-impedance plane |
| VCC | Power Supply | 2.7–3.6 V supply; includes internal POR circuit (~1.8 V threshold) to inhibit commands during ramp |
| WP | Write Protect | Hardware lockout for status register; active low only when WPEN bit = 1; prevents accidental config corruption |
| HOLD | Communication Suspend | Pauses ongoing SPI transfer without resetting sequence; requires SCK low before assertion |
Key Features
| Feature | Design Value |
|---|---|
| SPI Mode 0 & 3 Support | Ensures interoperability with legacy and modern microcontrollers (e.g., STM32, PIC32, NXP i.MX RT) without protocol translation |
| Flexible Block Write Protection | Eight software-selectable protection levels (1/64 to full array) via nonvolatile BP0–BP4 bits - enables secure boot partitioning |
| Self-Timed Erase/Program | Eliminates external timing control; RDSR polling (RDY bit) provides deterministic completion detection for real-time systems |
| Dual Package Options | Same die in 8S1 SOIC and 8Y7 SAP footprints - allows layout reuse across cost-sensitive and ultra-thin form factors |
| JEDEC RDID Compliance | 1Fh (Atmel) / 66h (AT25FS040) / 04h (4 Mbit) ID response - enables automated flash programmer recognition and BOM validation |
Applications
| Industrial PLC Firmware Storage | Medical Device Configuration Logging |
|---|---|
Use Scenario: Storing firmware images and calibration tables in programmable logic controllers deployed in factory-floor environments with wide temperature swings and EMI exposure. IC Role / Device Role / Timing Role: Nonvolatile boot memory and runtime parameter store; accessed via SPI during cold start and periodic configuration updates. Use Value: 10,000 write cycles and –40°C to +85°C rating ensure reliable field updates over 10+ years; sector erase enables patch deployment without full reflash downtime. |
Use Scenario: Recording sensor calibration offsets, usage counters, and audit trails in portable diagnostic equipment requiring traceable data integrity. IC Role / Device Role / Timing Role: Secure configuration register; write-protected upper sectors hold immutable calibration constants while lower sectors log timestamped events. Use Value: Hardware WP pin + software BP bits prevent unauthorized modification of medical calibration data; 30 µs/byte program time minimizes logging latency during patient monitoring. |
| Automotive Infotainment Bootloader | Smart Energy Meter Firmware Vault |
Use Scenario: Hosting primary bootloader and fail-safe recovery image in automotive head units where AEC-Q200 compliance is required for functional safety. IC Role / Device Role / Timing Role: SPI-connected boot memory; selected by microcontroller on power-up to load application firmware from verified address range. Use Value: Dual 64 KB block erase allows atomic swap between active/inactive firmware partitions; RDID verification ensures correct part insertion during manufacturing. |
Use Scenario: Storing tariff tables, firmware signatures, and tamper-event logs in utility-grade electricity meters operating continuously for 15+ years. IC Role / Device Role / Timing Role: Long-life data vault; accessed intermittently for firmware validation and daily log writes using page-mode programming. Use Value: Low 2.7 V operation extends battery backup life; 8-lead SOIC package withstands thermal cycling in outdoor meter enclosures; chip erase capability enables secure field decommissioning. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Winbond W25Q40EW | 4 Mbit density, same SOIC-8 package, but supports DTR mode and Quad SPI; 100k endurance vs. 10k | Better suited for high-speed code XIP or frequent firmware updates; lacks HOLD pin | Select if higher endurance or Quad SPI bandwidth is required; verify HOLD functionality not needed in target design |
| Micron MT25QL04A | 4 Mbit, SOIC-8, supports 133 MHz dual/quad SPI; 100k endurance; includes SFDP for auto-configuration | Enables dynamic command set negotiation; no native HOLD pin; requires different status register layout | Choose for advanced SPI features and future-proofing; avoid if HOLD suspend is mandatory for host controller compatibility |
Compared with W25Q40EW and MT25QL04A, the AT25FS040N-SH27-B offers guaranteed HOLD functionality, simpler status register mapping, and proven stability in legacy industrial SPI interfaces - making it optimal for cost-sensitive, long-lifecycle designs where feature parity outweighs raw speed or endurance.
Availability
AT25FS040N-SH27-B is available at Aetrix Electronics and suitable for industrial PLC firmware storage, medical device configuration logging, automotive infotainment bootloaders, and smart energy meter firmware vaults requiring stable component supply across extended product lifecycles.
Supply support for AT25FS040N-SH27-B 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
Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with a focus on reliability, longevity, and industrial-grade qualification.
The AT25FS040N-SH27-B belongs to Microchip's AT25FS family of high-reliability serial Flash memories designed specifically for industrial, medical, and automotive applications demanding robust data retention, low-voltage operation, and long-term supply assurance.
FAQ
What is the operating voltage range for the AT25FS040N-SH27-B?
The AT25FS040N-SH27-B operates from 2.7 V to 3.6 V, with absolute maximum ratings up to 4.2 V. This range ensures compatibility with standard 3.3 V logic systems and supports brown-out resilience in industrial power supplies. The device incorporates a Power-On Reset circuit that holds the IC inactive until VCC exceeds ~1.8 V, preventing spurious writes during power ramp.
Does the AT25FS040N-SH27-B support both SPI Mode 0 and Mode 3?
Yes, the AT25FS040N-SH27-B explicitly supports SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1), as confirmed in its official datasheet. Mode 0 operation is fully characterized and recommended for most applications. The dual-mode support allows seamless integration with diverse microcontrollers, including legacy 8-bit MCUs and modern ARM-based SoCs, without requiring protocol translation hardware.
How does hardware write protection work on the AT25FS040N-SH27-B?
Hardware write protection on the AT25FS040N-SH27-B is enabled via the WP pin, but only when the WPEN bit (Status Register Bit 7) is set to "1". When WP is low and WPEN = 1, all writes to the status register-including BP bits and WPEN itself-are inhibited. If WPEN = 0, the WP pin is ignored, allowing full status register configuration even with WP tied to ground - a key design flexibility for fixed-configuration systems.
What is the maximum clock frequency supported by the AT25FS040N-SH27-B?
The AT25FS040N-SH27-B supports a maximum SCK clock frequency of 50 MHz, as specified in its AC characteristics table. This enables high-speed read and program operations, with FAST READ achieving full throughput using dummy-cycle protocol. Timing parameters such as tWH/tWL (9 ns min) and tSU/tH (5 ns) are guaranteed across the full –40°C to +85°C industrial temperature range.
Can the AT25FS040N-SH27-B be used in place of older AT25DF041 devices?
The AT25FS040N-SH27-B is a functional successor to the AT25DF041, sharing identical pinout, density, and core SPI command set (WREN, RDSR, READ, PROGRAM, SECTOR ERASE). However, it adds HOLD pin support, improved 50 MHz timing, and enhanced write protection granularity. Migration requires verifying HOLD pin usage and updating status register interpretation per the AT25FS040N-SH27-B datasheet, but no PCB changes are needed.
AT25FS040N-SH27-B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 4Mbit
- Memory Organization:
- 512K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 50 MHz
- Write Cycle Time - Word, Page:
- 50µs
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT25FS040N-SH27-B FAQ
1.How can I place an order for AT25FS040N-SH27-B through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25FS040N-SH27-B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AT25FS040N-SH27-B reliable?
The price and inventory of AT25FS040N-SH27-B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT25FS040N-SH27-B is usually 5 days.
3.What payment methods are accepted for AT25FS040N-SH27-B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25FS040N-SH27-B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25FS040N-SH27-B?
AT25FS040N-SH27-B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25FS040N-SH27-B order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AT25FS040N-SH27-B?
For technical support, including AT25FS040N-SH27-B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25FS040N-SH27-B requirements.
6.How does Aetrix verify that AT25FS040N-SH27-B is sourced from the original manufacturer or authorized distributors?
All AT25FS040N-SH27-B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT25FS040N-SH27-B meets industry standards.
7.What is the process for return or replacement of AT25FS040N-SH27-B?
All AT25FS040N-SH27-B units undergo pre-shipment inspection (PSI). If there is an issue with AT25FS040N-SH27-B, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AT25FS040N-SH27-B part is unused and in its original packaging.
Return procedure for AT25FS040N-SH27-B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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