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Microchip Technology AT25256W-10SI-2.7
- Part No.:
- AT25256W-10SI-2.7
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT25256W-10SI-2.7.pdf
- Description:
- IC EEPROM 256KBIT SPI 3MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,550
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Product details
Overview
AT25256W-10SI-2.7 from Microchip Technology (formerly Atmel) is a 256 Kbit SPI serial EEPROM organized as 32,768 × 8-bit memory array, operating from 2.7V to 5.5V supply, supporting 3 MHz clock rate and 64-byte page write mode. It features hardware write protection via WP pin, HOLD suspend functionality, and block-level write protection for 1/4, 1/2, or full memory array - deployed in industrial control modules requiring nonvolatile parameter storage with low-power operation.
For engineers reviewing the AT25256W-10SI-2.7 datasheet, AT25256W-10SI-2.7 pinout, AT25256W-10SI-2.7 application, or AT25256W-10SI-2.7 equivalent, key selection criteria include verified 3 MHz SPI timing compliance, 5 ms typical write cycle time, VCC = 2.7–5.5 V operation range, 100,000 write endurance, and EIAJ SOIC-8 package compatibility with industrial temperature range (–40°C to +85°C).
Technical Context
The AT25256W-10SI-2.7 operates exclusively as an SPI slave device with separate SI (input) and SO (output) pins, supporting SPI Modes 0 and 3. Its internal instruction register accepts op-codes including WREN, WRITE, RDSR, and WRSR, with MSB-first data transfer initiated by CS falling edge.
Block write protection is implemented via nonvolatile BP0/BP1 bits in the status register, enabling selective locking of top 1/4 (6000–7FFFh), top 1/2 (4000–7FFFh), or entire (0000–7FFFh) memory space. The WPEN bit controls hardware write protection activation, and HOLD pin allows mid-transaction suspension without sequence reset.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8-bit array) - supports firmware configuration storage in resource-constrained embedded systems. |
| Supply Voltage | 2.7 V to 5.5 V - enables direct interface with 3.3 V and 5 V microcontrollers without level-shifting. |
| Max Clock Frequency | 3 MHz - ensures reliable high-speed read/write in SPI master-controlled timing budgets. |
| Write Cycle Time | 5 ms typical - defines minimum interval between successive write commands; impacts real-time logging latency. |
| Endurance | 100,000 write cycles - guarantees long-term reliability in field-updatable calibration or event-logging applications. |
| Data Retention | >200 years - ensures persistent storage integrity across product lifetime without refresh. |
| Operating Temp | –40°C to +85°C - validated for industrial-grade deployment in motor drives and sensor nodes. |
Pinout & Package
AT25256W-10SI-2.7 is housed in an 8-lead EIAJ SOIC package (8S2), 0.209" body width, with gull-wing leads and standard JEDEC-compliant footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; initiates SPI transaction on falling edge and latches first byte as op-code. |
| SCK | Serial Clock Input | Master-generated clock; synchronizes all SI/SO data transfers; supports up to 3 MHz. |
| SI | Serial Data Input | Receives op-codes, addresses, and write data; MSB-first, sampled on SCK rising edge (Mode 0). |
| SO | Serial Data Output | Drives read data and status bits; high-impedance when CS high or during HOLD/Write cycle. |
| WP | Write Protect | Hardware lock for status register and protected memory blocks when WPEN=1 and WP=low. |
| HOLD | Communication Suspend | Pauses ongoing SPI transfer without resetting address counter; requires SCK=low to assert. |
| VCC | Power Supply | 2.7–5.5 V input; powers internal logic and memory array; decoupling capacitor required. |
| GND | Ground Reference | Return path for VCC and all I/O signals; must be low-impedance connection to minimize noise. |
Key Features
| Feature | Design Value |
|---|---|
| SPI Mode Support | Compatible with Modes 0 (CPOL=0, CPHA=0) and 3 (CPOL=1, CPHA=1), ensuring interoperability with diverse MCU families. |
| Page Write Capability | 64-byte burst writes reduce transaction overhead versus byte-by-byte programming, improving firmware update efficiency. |
| Block Write Protection | Configurable via status register to lock top 1/4, 1/2, or full memory - prevents accidental overwrite of critical boot or calibration data. |
| Self-timed Write Cycle | No external erase step required; internal timing eliminates need for host-side delay management beyond tWC (5 ms typical). |
| Automotive-Grade Option | Extended temperature and lead-free variants available (e.g., AT25256W-10SE-2.7), supporting automotive subsystems with AEC-Q100 alignment. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data Retention |
|---|---|
Use Scenario: Storing I/O mapping tables, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory automation lines. IC Role / Device Role / Timing Role: Nonvolatile configuration memory interfaced via SPI to ARM Cortex-M7 host MCU; accessed during boot and runtime reconfiguration. Use Value: 100,000 write cycles and >200-year data retention ensure parameter integrity over 15+ year equipment lifetimes without maintenance. | Use Scenario: Holding factory-calibrated sensor offsets and gain coefficients in portable ultrasound units subject to frequent power cycling and field updates. IC Role / Device Role / Timing Role: SPI EEPROM providing deterministic read latency (<150 ns output valid) and robust write protection against unintended recalibration. Use Value: Block write protection (BP0/BP1) isolates calibration sector from user-adjustable settings, preventing corruption during firmware upgrades. |
| Automotive Body Control Module (BCM) | Smart Energy Meter Firmware Parameters |
Use Scenario: Storing seat position presets, mirror angles, and lighting profiles in BCMs where EEPROM must survive automotive temperature cycling and ESD events. IC Role / Device Role / Timing Role: Industrial-grade AT25256W-10SI-2.7 variant used with watchdog-timed SPI transactions to meet ASIL-B functional safety constraints. Use Value: –40°C to +85°C operation and 2.7–5.5 V supply range eliminate need for external voltage regulation in 12 V battery-supplied systems. | Use Scenario: Maintaining tariff schedules, pulse constants, and communication keys in ANSI C12.22-compliant smart meters with tamper-resistant firmware. IC Role / Device Role / Timing Role: Secure configuration store with dual protection: hardware WP pin and software WRSR-controlled BP bits. Use Value: WPEN-enabled hardware lock prevents unauthorized access even if MCU firmware is compromised, meeting ANSI C12.22 security requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT25256A-10SI-2.7 | Successor device with enhanced ESD rating (4 kV HBM), improved tWC consistency, and updated qualification per AEC-Q100 Rev G. | Preferred for new designs targeting automotive or high-reliability industrial use; same pinout and command set. | Select AT25256A-10SI-2.7 for production ramp due to active status and extended lifecycle support. |
| M95256-WMN6TP | STMicroelectronics 256 Kbit SPI EEPROM; identical 8-lead SOIC package, 2.7–5.5 V, but rated for 5 MHz max clock and 1 million write cycles. | Better suited for high-throughput logging applications requiring faster write throughput and longer endurance. | Choose M95256-WMN6TP when system SPI clock exceeds 3 MHz or >100K write cycles per unit lifetime are projected. |
Compared with AT25256W-10SI-2.7, AT25256A-10SI-2.7 offers backward-compatible reliability upgrades for automotive-grade deployments, while M95256-WMN6TP provides higher speed and endurance at the cost of different manufacturer qualification and minor AC timing variations.
Availability
AT25256W-10SI-2.7 is available at Aetrix Electronics and suitable for industrial PLCs, medical calibration systems, automotive body control modules, and smart energy meters requiring stable component supply across multi-year production cycles.
Supply support for AT25256W-10SI-2.7 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 nonvolatile memory solutions, with broad industrial and automotive qualification expertise.
The AT25256 series belongs to Microchip's legacy SPI EEPROM product line, designed specifically for robust, low-power, pin-efficient nonvolatile storage in space-constrained embedded systems requiring guaranteed data integrity.
FAQ
What is the maximum SPI clock frequency supported by AT25256W-10SI-2.7?
The AT25256W-10SI-2.7 supports a maximum SCK frequency of 3 MHz across its full 2.7–5.5 V supply range and –40°C to +85°C operating temperature. This value is specified in Table 4 (AC Characteristics) of the official datasheet and applies to both read and write operations under standard load conditions (CL = 1 TTL gate + 100 pF). Exceeding 3 MHz may result in setup/hold violations or data corruption.
Does AT25256W-10SI-2.7 require an external erase command before writing?
No, AT25256W-10SI-2.7 does not require a separate erase command. All write operations are self-timed and internally managed: the device automatically erases the target byte or page prior to programming. A Write Enable (WREN) instruction must precede each WRITE command, and the internal write cycle completes in 5 ms typical - after which the RDY bit clears in the status register.
How is write protection implemented on AT25256W-10SI-2.7?
AT25256W-10SI-2.7 implements dual-layer write protection: hardware-based via the WP pin (when WPEN=1 and WP=low), and software-configurable via BP0/BP1 bits in the status register. These bits define protected memory segments (none, top 1/4, top 1/2, or full array). Protection applies to both memory writes and status register modification, ensuring critical data remains immutable unless explicitly disabled.
What package type is used for AT25256W-10SI-2.7?
AT25256W-10SI-2.7 uses an 8-lead EIAJ SOIC package (designated 8S2), measuring 0.209" body width with gull-wing leads. This package is distinct from JEDEC SOIC (8S1) and is fully compatible with standard SOIC-8 footprints used in industrial PCB assembly. Pin 1 marking is a beveled corner, and the package meets RoHS and lead-free requirements.
Can AT25256W-10SI-2.7 operate at 1.8 V?
No, AT25256W-10SI-2.7 is specifically rated for 2.7 V to 5.5 V operation only. The "–2.7" suffix denotes the low-voltage 2.7 V variant, whereas 1.8 V operation requires the "–1.8" suffix (e.g., AT25256W-10SI-1.8). Attempting to power AT25256W-10SI-2.7 below 2.7 V may cause unreliable read/write behavior, status register corruption, or failure to respond to SPI commands.
AT25256W-10SI-2.7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 3 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT25256W-10SI-2.7 FAQ
1.How can I place an order for AT25256W-10SI-2.7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25256W-10SI-2.7 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 AT25256W-10SI-2.7 reliable?
The price and inventory of AT25256W-10SI-2.7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT25256W-10SI-2.7 is usually 5 days.
3.What payment methods are accepted for AT25256W-10SI-2.7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25256W-10SI-2.7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25256W-10SI-2.7?
AT25256W-10SI-2.7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25256W-10SI-2.7 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 AT25256W-10SI-2.7?
For technical support, including AT25256W-10SI-2.7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25256W-10SI-2.7 requirements.
6.How does Aetrix verify that AT25256W-10SI-2.7 is sourced from the original manufacturer or authorized distributors?
All AT25256W-10SI-2.7 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 AT25256W-10SI-2.7 meets industry standards.
7.What is the process for return or replacement of AT25256W-10SI-2.7?
All AT25256W-10SI-2.7 units undergo pre-shipment inspection (PSI). If there is an issue with AT25256W-10SI-2.7, 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 AT25256W-10SI-2.7 part is unused and in its original packaging.
Return procedure for AT25256W-10SI-2.7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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