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Microchip Technology AT25256AN-10SI-2.7
- Part No.:
- AT25256AN-10SI-2.7
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT25256AN-10SI-2.7.pdf
- Description:
- IC EEPROM 256KBIT SPI 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,813
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Product details
Overview
AT25256AN-10SI-2.7 from Microchip Technology (formerly Atmel) is a 256 Kbit SPI serial EEPROM organized as 32,768 × 8 bits, operating from 2.7V to 5.5V, supporting 20 MHz clock rate at 5V, featuring hardware/software write protection and 64-byte page write capability. It serves as nonvolatile configuration storage in industrial controllers, automotive body modules, and embedded sensor nodes requiring reliable low-voltage data retention.
For engineers reviewing the AT25256AN-10SI-2.7 datasheet, AT25256AN-10SI-2.7 pinout, AT25256AN-10SI-2.7 application, or AT25256AN-10SI-2.7 equivalent, key selection criteria include its JEDEC SOIC-8 package, 100,000 write endurance, >100-year data retention, block write protection granularity (1/4, 1/2, full array), and HOLD/CS-controlled suspend functionality for multi-master SPI environments.
Technical Context
The AT25256AN-10SI-2.7 implements a synchronous SPI slave interface with separate SI/SO pins, supports SPI modes 0 and 3, and uses MSB-first transmission with op-code–driven command set (WREN, WRITE, RDSR, WRSR). Its internal architecture includes a nonvolatile status register with BP0/BP1/WPEN bits controlling memory protection scope and WP pin enablement.
Write operations require explicit WREN instruction prior to WRITE; self-timed internal write cycles complete in ≤5 ms, during which only RDSR is accepted. The HOLD pin suspends ongoing SPI transfers without resetting sequence state, while WP provides hardware-level inhibition of status register writes when WPEN = 1 and WP = low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 262,144 bits (32,768 × 8), sufficient for firmware parameter tables or calibration data in resource-constrained systems. |
| Supply Voltage Range | 2.7V to 5.5V - enables direct integration with 3.3V and 5V microcontrollers without level-shifting. |
| Max Clock Frequency | 20 MHz at VCC = 5V - supports high-throughput configuration loading in real-time control loops. |
| Page Write Size | 64 bytes - minimizes write latency versus byte-write; allows efficient bulk updates of contiguous settings. |
| Endurance / Retention | 100,000 write cycles / >100 years - meets long-life requirements for industrial field devices and automotive ECUs. |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade deployment in harsh ambient conditions. |
| Package | 8-lead JEDEC SOIC (8S1), 150-mil width - standard footprint compatible with automated SMT assembly and legacy PCB layouts. |
Pinout & Package
AT25256AN-10SI-2.7 is housed in an 8-lead JEDEC-standard SOIC package (8S1), 0.150" wide body, with gull-wing leads and 1.27 mm pitch. Pin 1 is marked by a notch or dot; device orientation follows standard SOIC conventions.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable: initiates SPI communication; high-Z SO when CS high ensures bus isolation in multi-device systems. |
| SCK | Serial Clock Input | Master-generated clock; timing-critical path governing max 20 MHz operation and setup/hold compliance per AC specs. |
| SI | Serial Data Input | Receives op-codes, addresses, and write data; latched on SCK rising edge in Mode 0, falling edge in Mode 3. |
| SO | Serial Data Output | Drives read data and status bits; high-impedance when CS high or during HOLD - prevents bus contention. |
| WP | Write Protect | Hardware lock: disables status register writes when WPEN=1 and WP=low; independent of software WREN state. |
| HOLD | Communication Suspend | Pauses SPI transfer mid-sequence without reset; requires SCK low during assertion - essential for interrupt-driven masters. |
| VCC | Power Supply | 2.7V–5.5V input; decoupling capacitor required near pin to suppress switching noise affecting tWH/tWL margins. |
| GND | Ground Reference | Return path for all I/O and core logic; must be low-impedance connection to minimize ground bounce in high-speed reads. |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | Selectable 1/4, 1/2, or full-array protection via status register BP0/BP1 bits - prevents accidental overwrites of critical boot or calibration sectors. |
| Hardware + Software Write Lock | WP pin + WRSR instruction provide dual-layer security: WP blocks status register writes; WREN/WRDI manage volatile write-enable latch. |
| HOLD Functionality | Enables deterministic pause/resume of SPI transactions - eliminates need for retransmission after CPU interrupts or priority task preemption. |
| Self-Timed Write Cycle | No external erase step required; internal timing guarantees ≤5 ms completion - simplifies firmware design and avoids timeout polling complexity. |
| Industrial Temperature Range | −40°C to +85°C operation with guaranteed DC/AC specs - validated for use in motor drives, PLCs, and automotive cabin electronics. |
Applications
| Industrial PLC Configuration Storage | Automotive Body Control Module |
|---|---|
|
Use Scenario: Storing user-defined I/O mapping, scaling factors, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed via SPI during power-up and runtime reconfiguration. Use Value: Enables field-upgradable machine parameters without firmware reflashing; 100K endurance supports decades of maintenance cycles. |
Use Scenario: Retaining seat position memory, mirror angle presets, and lighting profiles across ignition cycles in automotive door modules. IC Role / Device Role / Timing Role: SPI-connected parameter store interfaced to 8-bit/32-bit MCU with HOLD support for seamless interrupt handling. Use Value: >100-year data retention ensures lifetime reliability; 2.7V min supply allows operation during battery brownout events. |
| Medical Sensor Calibration Data | Smart Energy Meter Firmware Settings |
|
Use Scenario: Holding factory-calibrated offset/gain coefficients for analog front-end sensors in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, write-protected memory segment accessed only during calibration mode via authenticated SPI commands. Use Value: Block protection prevents corruption of calibrated values; WP pin hardwires protection during production test. |
Use Scenario: Storing tariff schedules, metering constants, and tamper-detection flags in ANSI C12.22-compliant utility meters. IC Role / Device Role / Timing Role: Trusted configuration vault with hardware write disable, accessed during secure boot and firmware update verification. Use Value: Dual protection (WP + WRSR) meets IEC 62056 security requirements; 5 ms write time enables fast credential updates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| M95256-WMN6TP | STMicroelectronics 256 Kbit SPI EEPROM; identical 8-lead SOIC-8 package, 2.5–5.5V range, but rated for −40°C to +105°C and features faster 20 MHz max clock at 2.5V. | Preferred for extended temperature designs where 105°C upper limit is required; lacks HOLD pin - unsuitable for interrupt-sensitive hosts. | Select M95256-WMN6TP when extended temp rating is mandatory and HOLD functionality is not needed. |
| BR25L256FJ-WE2 | Rohm 256 Kbit SPI EEPROM; same SOIC-8 footprint, 2.5–5.5V, −40°C to +85°C, but offers 40 MHz max clock and built-in error correction code (ECC) for enhanced reliability. | Used in safety-critical applications requiring bit-error detection; ECC adds overhead but improves FIT rate in noisy EMI environments. | Choose BR25L256FJ-WE2 when system-level functional safety (IEC 61508 SIL-2) demands ECC-protected nonvolatile storage. |
Compared with AT25256AN-10SI-2.7, M95256-WMN6TP trades HOLD support for wider temperature range, while BR25L256FJ-WE2 adds ECC and higher speed at the cost of increased software complexity for ECC management.
Availability
AT25256AN-10SI-2.7 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, medical sensor calibration, smart energy meters, and embedded IoT gateways requiring stable component supply across multi-year production cycles.
Supply support for AT25256AN-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 acquired Atmel in 2016 and maintains full product support, qualification, and manufacturing continuity for the AT25xxx family of serial EEPROMs.
The AT25256AN-10SI-2.7 belongs to Microchip's industrial-grade SPI EEPROM product line, designed specifically for robust, low-power nonvolatile data storage in space-constrained embedded systems with stringent reliability requirements.
FAQ
What is the maximum clock frequency supported by AT25256AN-10SI-2.7?
The AT25256AN-10SI-2.7 supports up to 20 MHz SCK frequency at VCC = 5.0V, 10 MHz at VCC = 2.7V–3.6V, and 5 MHz at VCC = 1.8V–2.6V. These values are specified in the AC Characteristics table under fSCK parameter and are validated across the full industrial temperature range (−40°C to +85°C). Operation beyond these limits may result in timing violations or data corruption.
Does AT25256AN-10SI-2.7 support both SPI Mode 0 and Mode 3?
Yes, AT25256AN-10SI-2.7 explicitly supports SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1), as stated in the Features section. This dual-mode compatibility allows seamless integration with diverse microcontrollers including legacy 8051 derivatives (Mode 0) and modern ARM Cortex-M devices (often defaulting to Mode 3).
How does the HOLD pin function during active SPI communication in AT25256AN-10SI-2.7?
In AT25256AN-10SI-2.7, the HOLD pin suspends serial communication without resetting the internal address counter or command state. To activate HOLD, the pin must be driven low while SCK is low; resuming requires driving HOLD high while SCK remains low. During HOLD, SI is ignored and SO enters high-impedance - preserving bus integrity for multi-master arbitration.
What memory protection options are available on AT25256AN-10SI-2.7?
AT25256AN-10SI-2.7 provides three levels of block write protection via BP0/BP1 bits in the status register: none, top 1/4 (6000–7FFFh), top 1/2 (4000–7FFFh), or full array (0000–7FFFh). Protection is enforced independently of WP pin state when WPEN = 1, and can be configured using the WRSR instruction - enabling fine-grained safeguarding of critical firmware or calibration data.
Is AT25256AN-10SI-2.7 qualified for automotive applications?
AT25256AN-10SI-2.7 is specified for industrial temperature range (−40°C to +85°C) and carries Automotive Grade qualification per the datasheet's "Automotive Grade, Extended Temperature and Lead-free/Halogen-free Devices Available" statement. While not AEC-Q100 certified out-of-box, it is used in automotive body electronics where extended temp and reliability are required; full AEC-Q100 testing may be performed per customer request.
AT25256AN-10SI-2.7 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:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 20 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
AT25256AN-10SI-2.7 FAQ
1.How can I place an order for AT25256AN-10SI-2.7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25256AN-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 AT25256AN-10SI-2.7 reliable?
The price and inventory of AT25256AN-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 AT25256AN-10SI-2.7 is usually 5 days.
3.What payment methods are accepted for AT25256AN-10SI-2.7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25256AN-10SI-2.7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25256AN-10SI-2.7?
AT25256AN-10SI-2.7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25256AN-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 AT25256AN-10SI-2.7?
For technical support, including AT25256AN-10SI-2.7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25256AN-10SI-2.7 requirements.
6.How does Aetrix verify that AT25256AN-10SI-2.7 is sourced from the original manufacturer or authorized distributors?
All AT25256AN-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 AT25256AN-10SI-2.7 meets industry standards.
7.What is the process for return or replacement of AT25256AN-10SI-2.7?
All AT25256AN-10SI-2.7 units undergo pre-shipment inspection (PSI). If there is an issue with AT25256AN-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 AT25256AN-10SI-2.7 part is unused and in its original packaging.
Return procedure for AT25256AN-10SI-2.7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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