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Microchip Technology AT24C256C-XHL-T
- Part No.:
- AT24C256C-XHL-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
AT24C256C-XHL-T.pdf
- Description:
- IC EEPROM 256KBIT I2C 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:5,461
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Product details
Overview
AT24C256C-XHL-T from Microchip Technology is a 256-Kbit I²C-compatible serial EEPROM organized as 32,768 × 8 bits, operating from 1.7V to 5.5V across -40°C to +85°C. It supports 100 kHz standard mode, 400 kHz fast mode, and 1 MHz fast mode plus (FM+) with hardware write protection (WP), 64-byte page write, and ultra-low standby current (6 μA max). It is used in industrial control systems for nonvolatile parameter storage.
For engineers reviewing the AT24C256C-XHL-T datasheet, AT24C256C-XHL-T pinout, AT24C256C-XHL-T application, or AT24C256C-XHL-T equivalent, key selection criteria include I²C bus voltage compatibility (1.7–5.5 V), FM+ support at ≥2.5 V, WP pin functionality, 8-lead SOIC package dimensions, and endurance (1M write cycles) for long-life embedded logging.
Technical Context
The AT24C256C-XHL-T implements a two-wire I²C interface with Schmitt-triggered, noise-filtered SDA/SCL inputs and an open-drain SDA output requiring external pull-up. Its internal address decoder supports up to eight devices on one bus via A0–A2 hardware address pins.
It uses an integrated high-voltage generation circuit for EEPROM cell programming, enabling self-timed write cycles ≤5 ms, and includes a power-on reset (POR) circuit with 100 µs tPUP delay and 1.5 V VPOR threshold to prevent spurious writes during power ramp-up.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256 Kbit (32,768 × 8), enabling storage of firmware calibration data or device configuration tables |
| Interface | I²C-compatible two-wire (SCL/SDA), supporting standard (100 kHz), fast (400 kHz), and FM+ (1 MHz) modes |
| Supply voltage | 1.7 V to 5.5 V - interoperable with 1.8 V, 3.3 V, and 5 V microcontrollers without level shifters |
| Operating temperature | -40°C to +85°C industrial grade - suitable for factory automation and outdoor metering |
| Write endurance | 1,000,000 cycles - supports daily parameter updates over >27 years in field-deployed equipment |
| Data retention | 100 years at 55°C - ensures long-term reliability in unpowered storage scenarios |
| Standby current | ≤6 μA at 5.0 V - critical for battery-backed real-time clocks and energy-harvesting sensors |
| Page write size | 64 bytes with partial-page capability - reduces write latency when updating small configuration blocks |
Pinout & Package
AT24C256C-XHL-T is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with 150 mil body width, RoHS-compliant lead-free finish, and moisture sensitivity level (MSL) 3 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Hardware device address input | Configures LSB of 7-bit I²C slave address; pulled down internally if floating - must be tied to GND or VCC for deterministic multi-device bus addressing |
| A1 | Hardware device address input | Configures middle bit of 7-bit I²C slave address; enables up to eight AT24C256C-XHL-T devices on same bus |
| A2 | Hardware device address input | Configures MSB of 7-bit I²C slave address; combined with A0/A1, forms 3-bit hardware address (000–111) |
| GND | Ground reference | System ground return path; required for stable logic thresholds and ESD discharge path |
| SDA | Serial data bidirectional I/O | Open-drain line requiring external pull-up (≤10 kΩ); transmits/receives I²C data and ACK/NACK bits |
| SCL | Serial clock input | Input-only clock line; rising edge latches input data, falling edge outputs data - must be pulled high externally |
| WP | Hardware write-protect enable | Active-high signal: tied to VCC disables all writes to entire memory array; tied to GND enables normal operation |
| VCC | Power supply | 1.7–5.5 V core supply; powers internal charge pump for EEPROM programming and logic circuitry |
Key Features
| Feature | Design Value |
|---|---|
| FM+ support (1 MHz @ 2.5–5.5 V) | Enables faster configuration loading in time-critical boot sequences versus standard 400 kHz I²C |
| Schmitt-triggered, filtered inputs | Rejects >100 ns noise spikes on SCL/SDA - improves robustness in electrically noisy industrial environments |
| 64-byte page write with partial capability | Allows writing 1–64 bytes per command without erasing full page - minimizes wear and latency for small updates |
| Internal power-on reset (POR) | Guarantees device remains in standby until VCC stabilizes above 1.5 V and tPUP (100 µs) elapses - prevents corruption during brown-out |
| Green packaging (RoHS/halide-free) | Complies with global environmental regulations for industrial and consumer electronics manufacturing |
Applications
| Industrial PLC Configuration Storage | Smart Meter Firmware Parameter Backup |
|---|---|
Use Scenario: Storing calibrated sensor offsets, PID loop gains, and communication settings in programmable logic controllers deployed in factory floors. IC Role / Device Role / Timing Role: Nonvolatile configuration register - retains values across power cycles and supports infrequent writes (<100/day) with guaranteed 100-year data retention. Use Value: Eliminates need for battery-backed SRAM; reduces BOM cost and field failure risk from capacitor aging or leakage. | Use Scenario: Backing up tariff schedules, billing counters, and cryptographic keys in utility smart meters exposed to wide ambient temperature swings. IC Role / Device Role / Timing Role: Secure, low-power parameter vault - WP pin prevents accidental overwrites during firmware updates; 6 μA standby current extends battery life in tamper-detection circuits. Use Value: Meets ANSI C12.1 and IEC 62056 requirements for data integrity under intermittent power and thermal stress. |
| Medical Device Calibration Data Archive | Automotive Body Control Module Settings |
Use Scenario: Archiving factory-calibrated ADC gain/offset coefficients and user-adjusted therapy parameters in portable diagnostic equipment. IC Role / Device Role / Timing Role: Tamper-resistant calibration memory - write-protection ensures regulatory compliance (IEC 62304) by preventing unauthorized modification of safety-critical values. Use Value: Avoids re-certification costs when replacing main MCU; enables field recalibration without full device rework. | Use Scenario: Storing seat position presets, mirror angles, and lighting profiles in automotive body control modules (BCM) with CAN/LIN interfaces. IC Role / Device Role / Timing Role: Persistent user preference store - operates reliably at -40°C cold cranking and +85°C under-hood conditions; 1.7 V min VCC supports start-stop system brown-outs. Use Value: Enables seamless personalization across vehicle platforms without adding discrete backup capacitors or supercaps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STMicroelectronics M24256-BWMN6TP | Same 256 Kbit capacity, 1.7–5.5 V, -40°C to +85°C, but supports only up to 400 kHz I²C (no FM+); WP pin active-low | Lacks 1 MHz FM+ timing - unsuitable for high-throughput boot-time configuration loads | Select when FM+ is unnecessary and active-low WP matches existing board-level logic design |
| ON Semiconductor CAT24C256HU4IGT3 | Identical 256 Kbit, 1.7–5.5 V, -40°C to +85°C, and FM+ support; differs in SOIC marking and tape-and-reel packaging | No functional difference - pinout, timing, and DC specs match AT24C256C-XHL-T exactly | Drop-in alternative with identical electrical behavior; verify reel orientation and date code traceability for production continuity |
Compared with M24256-BWMN6TP, AT24C256C-XHL-T delivers 2.5× faster configuration writes via FM+; versus CAT24C256HU4IGT3, it offers identical performance but different logistics packaging - both alternatives require no PCB changes, though WP polarity must be verified for the ST part.
Availability
AT24C256C-XHL-T is available at Aetrix Electronics and suitable for industrial control systems, smart metering infrastructure, medical diagnostics equipment, and automotive body electronics requiring stable component supply across extended product lifecycles.
Supply support for AT24C256C-XHL-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 is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with ISO 9001-certified manufacturing and global distribution.
The AT24C256C-XHL-T belongs to Microchip's AT24Cxx family of I²C serial EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in space-constrained industrial and automotive applications.
FAQ
What is the maximum I²C clock frequency supported by the AT24C256C-XHL-T?
The AT24C256C-XHL-T supports three I²C speed modes: 100 kHz (standard mode), 400 kHz (fast mode), and 1 MHz (fast mode plus, FM+). FM+ operation requires VCC ≥2.5 V. All modes are fully compliant with I²C bus specifications and validated across the full industrial temperature range (-40°C to +85°C). The AT24C256C-XHL-T achieves this using integrated Schmitt triggers and noise filtering on SDA/SCL inputs.
Does the AT24C256C-XHL-T require external pull-up resistors on SDA and SCL lines?
Yes, the AT24C256C-XHL-T requires external pull-up resistors on both SDA and SCL lines because SDA is open-drain and SCL is an input-only pin. Microchip specifies maximum pull-up values of 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz FM+ operation. These values ensure rise times meet AC timing requirements (tR ≤ 300 ns) while maintaining noise immunity. The AT24C256C-XHL-T does not include internal pull-ups.
How does the Write-Protect (WP) pin function on the AT24C256C-XHL-T?
The WP pin on the AT24C256C-XHL-T is an active-high hardware write-protection signal. When WP is driven to VCC, all write operations (byte, page, and erase) to the entire 256-Kbit memory array are inhibited. When WP is tied to GND, normal write operations are enabled. If left floating, WP is internally pulled down to GND, enabling writes - but Microchip recommends hard-wiring WP to avoid noise-induced glitches. This behavior is documented in the AT24C256C-XHL-T datasheet Section 2.5.
What is the endurance and data retention specification for the AT24C256C-XHL-T?
The AT24C256C-XHL-T guarantees 1,000,000 write cycles per memory location and 100 years of data retention at 55°C. Endurance testing is performed at TA = 25°C and VCC = 3.3 V; retention is characterized at elevated temperature to accelerate aging. These figures apply to the full memory array and are validated per JEDEC standards. The AT24C256C-XHL-T achieves this using oxide-nitride-oxide (ONO) floating-gate technology and on-chip charge-pump regulation.
Is the AT24C256C-XHL-T compatible with other devices in the AT24Cxx family?
Yes, the AT24C256C-XHL-T is pin-compatible and protocol-compatible with other 8-pin SOIC-packaged AT24Cxx EEPROMs (e.g., AT24C02, AT24C128), sharing identical pinout (A0–A2, GND, SDA, SCL, WP, VCC), I²C addressing scheme (1010xxxR/W), and command set. However, memory size, page size, and write cycle time differ - e.g., AT24C256C-XHL-T has 64-byte pages and 5 ms max write time, whereas AT24C128 uses 64-byte pages but 10 ms max. System firmware must account for these differences.
AT24C256C-XHL-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- 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:
- 5ms
- Access Time:
- 550 ns
- Voltage - Supply:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
AT24C256C-XHL-T FAQ
1.How can I place an order for AT24C256C-XHL-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT24C256C-XHL-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 AT24C256C-XHL-T reliable?
The price and inventory of AT24C256C-XHL-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT24C256C-XHL-T is usually 5 days.
3.What payment methods are accepted for AT24C256C-XHL-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT24C256C-XHL-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT24C256C-XHL-T?
AT24C256C-XHL-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT24C256C-XHL-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 AT24C256C-XHL-T?
For technical support, including AT24C256C-XHL-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT24C256C-XHL-T requirements.
6.How does Aetrix verify that AT24C256C-XHL-T is sourced from the original manufacturer or authorized distributors?
All AT24C256C-XHL-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 AT24C256C-XHL-T meets industry standards.
7.What is the process for return or replacement of AT24C256C-XHL-T?
All AT24C256C-XHL-T units undergo pre-shipment inspection (PSI). If there is an issue with AT24C256C-XHL-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 AT24C256C-XHL-T part is unused and in its original packaging.
Return procedure for AT24C256C-XHL-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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