My Inquiry
My Account
Microchip Technology AT25256AW-10SI-1.8-T
- Part No.:
- AT25256AW-10SI-1.8-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT25256AW-10SI-1.8-T.pdf
- Description:
- IC EEPROM 256KBIT SPI 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,832
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT25256AW-10SI-1.8-T from Microchip Technology (formerly Atmel) is a 256 Kbit SPI serial EEPROM organized as 32,768 × 8 bits, operating from 1.8 V to 5.5 V, supporting 20 MHz clock rate at 5 V, featuring hardware write protection via WP pin and HOLD suspend functionality, and used in automotive and industrial microcontroller-based systems for nonvolatile parameter storage.
For engineers reviewing the AT25256AW-10SI-1.8-T datasheet, AT25256AW-10SI-1.8-T pinout, AT25256AW-10SI-1.8-T application, or AT25256AW-10SI-1.8-T equivalent, this page delivers verified electrical specs, JEDEC SOIC-8 package mapping, SPI Mode 0/3 timing compliance, 100,000 write-cycle endurance, and real-world use cases in automotive body control modules, industrial PLCs, and embedded sensor calibration.
Technical Context
The AT25256AW-10SI-1.8-T implements a synchronous SPI slave interface with separate SI (input) and SO (output) pins, MSB-first data transfer, and chip-select–driven op-code decoding. It supports both SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), with no erase cycle required prior to write.
Internal architecture includes an 8-bit instruction register, nonvolatile status register (WPEN, BP1/BP0, WEN, RDY), and automatic address incrementing during 64-byte page writes. Block write protection covers top 1/4, top 1/2, or entire memory array, configurable via WRSR instruction and enforced by hardware when WPEN=1 and WP=low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8), sufficient for firmware configuration tables or sensor calibration data in space-constrained designs |
| Supply Voltage Range | 1.8 V to 5.5 V - enables direct interfacing with 1.8 V logic families and backward compatibility with 3.3 V/5 V systems |
| Max Clock Frequency | 20 MHz at VCC = 5 V - supports high-throughput parameter updates without CPU polling overhead |
| Write Endurance | 100,000 cycles - meets automotive module lifetime requirements for recalibration events over 15+ years |
| Data Retention | >100 years at 25°C - ensures long-term integrity of stored calibration coefficients and security keys |
| Write Cycle Time | 5 ms max - defines minimum interval between successive write commands; critical for real-time logging applications |
| Operating Temperature | −40°C to +85°C - qualified for industrial and automotive under-hood environments |
Pinout & Package
AT25256AW-10SI-1.8-T is housed in an 8-lead JEDEC SOIC package (8S1), 0.150" wide, with standard gull-wing leads and RoHS-compliant lead-free/halogen-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable signal; must be low to accept op-codes and data; high-Z SO when CS high |
| SCK | Serial Clock Input | Master-generated clock; sampling edge defined by SPI mode; must be low during HOLD assertion |
| SI | Serial Data Input | Accepts op-codes, addresses, and write data; ignored during HOLD or internal write cycle |
| SO | Serial Data Output | Drives read data or status bits; enters high-impedance state when CS high or HOLD active |
| GND | Ground Reference | Signal and power return path; decoupling capacitor must be placed within 5 mm of VCC/GND pins |
| VCC | Power Supply | 1.8 V to 5.5 V input; requires local 100 nF ceramic bypass capacitor adjacent to pin |
| WP | Hardware Write Protect | Low-active pin that blocks status register and protected memory writes when WPEN=1 |
| HOLD | Communication Suspend | Pauses ongoing SPI transaction without resetting sequence; requires SCK low before assertion |
Key Features
| Feature | Design Value |
|---|---|
| SPI Mode 0 & 3 Support | Interoperable with diverse MCUs including ARM Cortex-M, Renesas RL78, and TI MSP430 without level-shifting or protocol translation |
| 64-byte Page Write | Reduces firmware overhead by enabling burst programming of calibration datasets in single command sequences |
| Block Write Protection | Configurable via status register to lock top 1/4 (6000–7FFFh), top 1/2 (4000–7FFFh), or full array (0000–7FFFh) |
| Self-timed Write Cycle | No external timing control needed; RDSR polling confirms completion; eliminates need for fixed delay loops |
| Automotive Grade Qualification | Meets AEC-Q100 stress test requirements for temperature cycling, HTOL, and ESD robustness in vehicle ECUs |
Applications
| Automotive Body Control Module | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing door lock actuator calibration offsets and seat position presets across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile parameter memory interfaced directly to an 8-bit MCU via 3-wire SPI, accessed during boot initialization. Use Value: Enables field-upgradable calibration without requiring external voltage supervisors or backup batteries. |
Use Scenario: Retaining I/O mapping tables and alarm thresholds after power loss in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: SPI EEPROM providing deterministic 5 ms write latency and >100-year data retention for mission-critical settings. Use Value: Eliminates reliance on supercapacitors or battery-backed SRAM, reducing BOM cost and failure modes. |
| Medical Sensor Calibration Hub | Smart Energy Meter Firmware Patch Storage |
Use Scenario: Holding factory-trimmed gain/offset coefficients for analog front-end sensors in portable diagnostic devices. IC Role / Device Role / Timing Role: Low-power (0.2 µA standby at 1.8 V) serial memory accessed only during device startup or recalibration events. Use Value: Supports 1.8 V operation to match ultra-low-power sensor signal chains while maintaining 100,000-cycle endurance. |
Use Scenario: Storing signed firmware patches downloaded over HAN (Home Area Network) for secure over-the-air updates. IC Role / Device Role / Timing Role: Secure nonvolatile storage with hardware WP pin and status-register–based block protection preventing accidental overwrite. Use Value: Enables tamper-resistant patch deployment without requiring dedicated secure elements or cryptographic accelerators. |
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; 2.5–5.5 V supply; 20 MHz max; SOIC-8; identical pinout and instruction set | Qualified to AEC-Q100 Grade 2 (−40°C to +105°C); slightly higher ISB3 (5 µA vs 2 µA at 5 V) | Drop-in replacement where extended temperature range is required; same PCB layout and firmware |
| BR25V256FJ-WE2 | Rohm 256 Kbit SPI EEPROM; 1.7–5.5 V supply; 10 MHz max; 8-pin TSSOP; supports SPI Mode 0 only | Lower max clock rate limits throughput; smaller TSSOP-8 footprint (3.0 × 4.4 mm vs SOIC-8's 3.9 × 4.9 mm) | Preferred for space-constrained designs accepting reduced speed; requires layout change and firmware timing adjustment |
Compared with AT25256AW-10SI-1.8-T, M95256-WMN6TP offers identical functionality with extended temperature qualification, while BR25V256FJ-WE2 trades speed and package compatibility for compactness-making the former ideal for automotive upgrades and the latter for consumer IoT miniaturization.
Availability
AT25256AW-10SI-1.8-T is available at Aetrix Electronics and suitable for automotive body control units, industrial PLCs, medical sensor calibration hubs, and smart energy meter firmware patch storage requiring stable component supply across multi-year production cycles.
Supply support for AT25256AW-10SI-1.8-T 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, documentation, and manufacturing continuity for the AT25xxx family of serial EEPROMs.
The AT25256AW-10SI-1.8-T belongs to Microchip's SPI Serial EEPROM product line, designed specifically for reliable, low-voltage nonvolatile storage in automotive, industrial, and medical systems demanding long data retention and robust write protection.
FAQ
What is the maximum clock frequency supported by the AT25256AW-10SI-1.8-T?
The AT25256AW-10SI-1.8-T supports up to 20 MHz SCK frequency at VCC = 5.0 V, 10 MHz at VCC = 2.7–3.6 V, and 5 MHz at VCC = 1.8–2.7 V. These values are specified in the AC Characteristics table and reflect guaranteed timing margins across temperature and voltage ranges. The AT25256AW-10SI-1.8-T must not be operated above these limits to ensure reliable read/write operation.
Does the AT25256AW-10SI-1.8-T require an external erase cycle before writing?
No, the AT25256AW-10SI-1.8-T does not require a separate erase cycle. Each byte or page write automatically erases and reprograms the target location. This simplifies firmware implementation, as only WREN followed by WRITE instructions are needed. The AT25256AW-10SI-1.8-T handles all erase/write sequencing internally, with self-timed completion confirmed via RDSR polling.
How does hardware write protection work on the AT25256AW-10SI-1.8-T?
Hardware write protection on the AT25256AW-10SI-1.8-T is enabled when the WP pin is pulled low AND the WPEN bit (bit 7 of status register) is set to 1. When active, it prevents writes to the status register and any memory addresses covered by BP0/BP1 protection bits. The AT25256AW-10SI-1.8-T remains readable, and unprotected memory regions remain writable.
Can the AT25256AW-10SI-1.8-T be used in SPI Mode 1 or Mode 2?
No, the AT25256AW-10SI-1.8-T explicitly supports only SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), as stated in its Features section and verified in the Serial Interface description. Attempting Mode 1 or Mode 2 will result in incorrect data sampling and communication failure. The AT25256AW-10SI-1.8-T does not decode clock polarity or phase outside these two modes.
What is the purpose of the HOLD pin on the AT25256AW-10SI-1.8-T?
The HOLD pin on the AT25256AW-10SI-1.8-T suspends ongoing SPI communication without resetting the internal command sequence. When asserted low (with SCK low), it places SO in high-impedance and ignores SI inputs until de-asserted. This allows a master MCU to service higher-priority interrupts and resume exactly where it left off. The AT25256AW-10SI-1.8-T retains full context across HOLD assertion.
AT25256AW-10SI-1.8-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT25256AW-10SI-1.8-T FAQ
1.How can I place an order for AT25256AW-10SI-1.8-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25256AW-10SI-1.8-T 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 AT25256AW-10SI-1.8-T reliable?
The price and inventory of AT25256AW-10SI-1.8-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT25256AW-10SI-1.8-T is usually 5 days.
3.What payment methods are accepted for AT25256AW-10SI-1.8-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25256AW-10SI-1.8-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25256AW-10SI-1.8-T?
AT25256AW-10SI-1.8-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25256AW-10SI-1.8-T 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 AT25256AW-10SI-1.8-T?
For technical support, including AT25256AW-10SI-1.8-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25256AW-10SI-1.8-T requirements.
6.How does Aetrix verify that AT25256AW-10SI-1.8-T is sourced from the original manufacturer or authorized distributors?
All AT25256AW-10SI-1.8-T 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 AT25256AW-10SI-1.8-T meets industry standards.
7.What is the process for return or replacement of AT25256AW-10SI-1.8-T?
All AT25256AW-10SI-1.8-T units undergo pre-shipment inspection (PSI). If there is an issue with AT25256AW-10SI-1.8-T, 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 AT25256AW-10SI-1.8-T part is unused and in its original packaging.
Return procedure for AT25256AW-10SI-1.8-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT25256AW-10SI-1.8-T Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
