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Microchip Technology AT24C256W-10SU-2.7
- Part No.:
- AT24C256W-10SU-2.7
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
AT24C256W-10SU-2.7.pdf
- Description:
- IC EEPROM 256KBIT I2C 1MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,879
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Product details
Overview
AT24C256W-10SU-2.7 from Microchip Technology (formerly Atmel) is a 256 Kbit (32,768 × 8) two-wire serial EEPROM optimized for low-voltage industrial applications. It operates from 2.7V to 5.5V, supports 400 kHz I²C bus speed at 2.7V, features hardware write protection via the WP pin, and delivers 1 million write cycles with 40-year data retention. It is used in embedded systems for parameter storage, calibration data logging, and configuration backup.
For engineers reviewing the AT24C256W-10SU-2.7 datasheet, AT24C256W-10SU-2.7 pinout, AT24C256W-10SU-2.7 application, or AT24C256W-10SU-2.7 equivalent, key selection considerations include its 8-lead SOIC (EIAJ) package, 64-byte page write capability, Schmitt-triggered noise-immune inputs, extended industrial temperature range (–40°C to +85°C), and RoHS-compliant green packaging.
Technical Context
The AT24C256W-10SU-2.7 implements a standard I²C-compatible two-wire interface with open-drain SDA and edge-triggered SCL, supporting up to four devices on a shared bus via A0/A1 address pins. Its internal architecture organizes memory as 512 pages of 64 bytes each, enabling efficient partial-page writes without rollover across page boundaries when limited to ≤64 bytes per transaction.
It uses an internally biased address and write-protect logic that pulls A0, A1, and WP low if left floating (capacitive coupling <3 pF), ensuring predictable default behavior. The device enters low-power standby mode after STOP condition receipt and supports acknowledge polling to detect write completion-critical for deterministic firmware timing in real-time systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8 bits), sufficient for storing full device configuration sets or firmware metadata in resource-constrained microcontrollers. |
| Supply Voltage Range | 2.7V to 5.5V - compatible with 3.3V and 5V logic domains without level shifting. |
| I²C Clock Frequency | 400 kHz at 2.7V - enables fast parameter updates while maintaining noise immunity in electrically noisy industrial environments. |
| Write Cycle Time | Max 5 ms (process-B variant) - defines minimum inter-write delay for reliable nonvolatile storage in time-critical logging sequences. |
| Endurance & Retention | 1 million write cycles / 40 years data retention - validated for long-life field deployment in metering, PLCs, and medical diagnostics equipment. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade operation without derating in uncontrolled ambient conditions. |
| Package | 8-lead EIAJ SOIC (8S2) - surface-mount footprint compatible with standard reflow profiles and automated assembly lines. |
Pinout & Package
AT24C256W-10SU-2.7 is supplied in an 8-lead EIAJ SOIC package (package code 8S2), measuring 5.13 mm × 7.70 mm × 1.70 mm (L × W × H), with gull-wing leads and RoHS-compliant matte-tin plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Device Address Input | Hardwired or floated to select one of four possible I²C addresses (1010A1A0xx); internal pull-down ensures safe default when unconnected. |
| A1 | Device Address Input | Second address bit enabling multi-device bus topology; same internal biasing as A0 for robust floating-state behavior. |
| NC | No Connect | Unbonded die pad - must remain unconnected on PCB to avoid parasitic coupling or latch-up risk. |
| GND | Ground Reference | Primary return path for VCC and I/O currents; requires low-impedance connection to system ground plane to maintain noise margin. |
| VCC | Power Supply | 2.7V–5.5V supply input; decoupling capacitor (0.1 µF ceramic) required within 5 mm for stable I²C signaling and write reliability. |
| WP | Write Protect Control | Active-high hardware lock: tied to VCC disables all writes; tied to GND enables normal operation; internal pull-down prevents accidental write enable. |
| SCL | Serial Clock Input | Positive-edge sampled clock for synchronous data transfer; requires external pull-up resistor (typically 2.2–10 kΩ) to VCC. |
| SDA | Serial Data I/O | Bidirectional open-drain bus line shared across multiple I²C devices; requires same external pull-up as SCL and supports wire-OR arbitration. |
Key Features
| Feature | Design Value |
|---|---|
| Schmitt-trigger inputs | Suppresses high-frequency noise on SCL/SDA lines, enabling reliable communication in EMI-prone industrial enclosures without external filtering. |
| 64-byte page write mode | Reduces firmware overhead by allowing burst writes up to 64 bytes per transaction, cutting total write time by >90% vs. byte-by-byte programming. |
| Hardware + software write protection | WP pin provides immediate physical lockout; combined with software address locking, it prevents accidental or malicious corruption of critical calibration tables. |
| Self-timed write cycle | Eliminates need for precise firmware timing loops - host MCU can poll ACK or use fixed 5 ms delay before next access. |
| Extended temperature qualification | Validated operation from –40°C to +85°C ensures consistent performance in outdoor metering, factory automation, and transportation electronics. |
Applications
| Smart Energy Meters | Industrial PLCs |
|---|---|
Use Scenario: Storing tariff schedules, metering registers, and tamper-event logs in electricity/water/gas meters deployed outdoors. IC Role / Device Role / Timing Role: Nonvolatile configuration and event-history storage with guaranteed 40-year data retention under thermal cycling and power interruption. Use Value: Eliminates battery-backed SRAM, reducing BOM cost and field failure risk while meeting ANSI C12.22 and IEC 62056 compliance requirements. | Use Scenario: Saving ladder logic state, I/O mapping, and calibration coefficients in programmable logic controllers operating in factory-floor environments. IC Role / Device Role / Timing Role: Persistent parameter storage accessible via microcontroller's I²C peripheral during boot and runtime reconfiguration. Use Value: Enables zero-downtime firmware updates and field recalibration without requiring external programming tools or service visits. |
| Medical Diagnostic Devices | Automotive Infotainment Modules |
Use Scenario: Recording sensor calibration offsets, usage counters, and diagnostic fault history in portable ultrasound or blood glucose analyzers. IC Role / Device Role / Timing Role: Secure, low-power memory for FDA-regulated traceability data with write-protection enforced during normal operation. Use Value: Meets IEC 62304 software lifecycle requirements for Class B medical devices through deterministic write endurance and retention validation. | Use Scenario: Storing user preferences, radio presets, and display brightness settings in automotive head units exposed to wide thermal swings. IC Role / Device Role / Timing Role: I²C-connected nonvolatile memory interfaced directly to MCU without voltage translation, supporting 125°C junction temperature derating. Use Value: Maintains user experience continuity across ignition cycles and battery disconnect events while complying with AEC-Q200 stress test requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT24C256B-SSHL-T | Same 256K capacity, 2.7–5.5V, but in 8-lead JEDEC SOIC (8S1); process-B revision guarantees 1M write cycles and extended temp support. | Identical functional scope; differs only in package outline (JEDEC vs. EIAJ SOIC) and tape-and-reel packaging format. | Select when JEDEC SOIC footprint compatibility or higher-volume tape-and-reel handling is required. |
| M24256-BWMN6TP | STMicroelectronics 256K I²C EEPROM, 2.5–5.5V, 400 kHz, 8-lead TSSOP (8A2), 1M write cycles, –40°C to +125°C rating. | Broader temperature range and different package; pinout incompatible due to TSSOP lead arrangement and VCC/GND placement. | Choose for extended high-temp operation (>85°C) or where TSSOP footprint aligns with existing layout constraints. |
Compared with AT24C256W-10SU-2.7, AT24C256B-SSHL-T offers identical electrical behavior in a JEDEC-standard SOIC, while M24256-BWMN6TP extends operational range to +125°C but requires PCB redesign due to TSSOP pinout and thermal pad requirements.
Availability
AT24C256W-10SU-2.7 is available at Aetrix Electronics and suitable for smart energy meters, industrial PLCs, medical diagnostic devices, and automotive infotainment modules requiring stable component supply across multi-year production lifecycles.
Supply support for AT24C256W-10SU-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 memory solutions, with a focus on reliability, longevity, and industrial-grade qualification.
The AT24C256 series belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems needing robust nonvolatile storage with minimal external components and proven field reliability.
FAQ
What is the maximum I²C clock frequency supported by AT24C256W-10SU-2.7 at 2.7V?
The AT24C256W-10SU-2.7 supports up to 400 kHz I²C clock frequency when operated at 2.7V, as specified in Table 5 (AC Characteristics – Extended Temperatures). This is lower than its 1 MHz rating at 5.0V but ensures timing margin and noise immunity in low-voltage industrial applications where supply regulation may be marginal.
Does AT24C256W-10SU-2.7 require external pull-up resistors on SDA and SCL lines?
Yes, AT24C256W-10SU-2.7 requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and speed; 4.7 kΩ is commonly used for 400 kHz operation with ≤400 pF total bus load, as confirmed in the AC measurement conditions section.
How does the WP pin function on AT24C256W-10SU-2.7, and what happens if it is left unconnected?
The WP pin on AT24C256W-10SU-2.7 is an active-high hardware write protect. When tied to VCC, all write operations are inhibited. If left unconnected, the internal circuit pulls WP low (GND) when capacitive coupling to VCC is <3 pF - enabling writes by default. Atmel recommends hardwiring WP to GND or VCC for deterministic behavior in production designs.
Can AT24C256W-10SU-2.7 be used in place of AT24C256B-SSHL-T without PCB changes?
No, AT24C256W-10SU-2.7 cannot be used as a drop-in replacement for AT24C256B-SSHL-T without PCB changes because they use different SOIC variants: AT24C256W-10SU-2.7 is in 8-lead EIAJ SOIC (8S2, 0.209" body width), while AT24C256B-SSHL-T uses 8-lead JEDEC SOIC (8S1, 0.150" body width). Footprint and solder mask dimensions differ, requiring layout revision.
What is the page size and maximum write length per transaction for AT24C256W-10SU-2.7?
AT24C256W-10SU-2.7 has a 64-byte page size and supports up to 64 bytes per page write transaction. Writing beyond 64 bytes causes address rollover within the same page - overwriting earlier data. To avoid corruption, firmware must enforce page-aligned boundaries and limit burst writes to ≤64 bytes, as documented in the Page Write section.
AT24C256W-10SU-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:
- I2C
- Clock Frequency:
- 1 MHz
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- 550 ns
- Voltage - Supply:
- 2.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AT24C256W-10SU-2.7 FAQ
1.How can I place an order for AT24C256W-10SU-2.7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT24C256W-10SU-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 AT24C256W-10SU-2.7 reliable?
The price and inventory of AT24C256W-10SU-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 AT24C256W-10SU-2.7 is usually 5 days.
3.What payment methods are accepted for AT24C256W-10SU-2.7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT24C256W-10SU-2.7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT24C256W-10SU-2.7?
AT24C256W-10SU-2.7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT24C256W-10SU-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 AT24C256W-10SU-2.7?
For technical support, including AT24C256W-10SU-2.7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT24C256W-10SU-2.7 requirements.
6.How does Aetrix verify that AT24C256W-10SU-2.7 is sourced from the original manufacturer or authorized distributors?
All AT24C256W-10SU-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 AT24C256W-10SU-2.7 meets industry standards.
7.What is the process for return or replacement of AT24C256W-10SU-2.7?
All AT24C256W-10SU-2.7 units undergo pre-shipment inspection (PSI). If there is an issue with AT24C256W-10SU-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 AT24C256W-10SU-2.7 part is unused and in its original packaging.
Return procedure for AT24C256W-10SU-2.7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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