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Microchip Technology 24FC256T-E/OT
- Part No.:
- 24FC256T-E/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SC-74A, SOT-753
- Datasheet:
-
24FC256T-E/OT.pdf
- Description:
- IC EEPROM 256KBIT I2C SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,887
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Product details
Overview
24FC256T-E/OT from Microchip Technology is a 256-Kbit I²C serial EEPROM with 32K × 8 organization, 1.7V–5.5V single-supply operation, 1 MHz maximum clock frequency (at VCC ≥ 2.5V), hardware write-protect (WP), and 64-byte page write buffer. It serves as nonvolatile configuration storage in embedded control systems requiring low-voltage compatibility and high endurance.
For engineers reviewing the 24FC256T-E/OT datasheet, 24FC256T-E/OT pinout, 24FC256T-E/OT application, or 24FC256T-E/OT equivalent, key selection criteria include its 1 MHz I²C speed at 2.5–5.5V, industrial/extended temperature support (−40°C to +125°C), SOT-23-5 package footprint, and guaranteed 1 million erase/write cycles with >200-year data retention.
Technical Context
The 24FC256T-E/OT implements a two-wire I²C-compatible interface with Schmitt-trigger inputs and slew-rate-controlled outputs to suppress noise and eliminate ground bounce. Its internal architecture includes a 64-byte page latch, address pointer, and self-timed write cycle controller that manages erase-before-write operations without external timing.
It supports cascaded bus configurations via three hardware address pins (A2/A1/A0) - though these are unconnected in the SOT-23-5 package - and uses acknowledge polling to signal write completion. The WP pin provides hardware-level protection of the full 256-Kbit array when tied to VCC.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8), enabling storage of firmware parameters, calibration data, or device IDs in space-constrained designs |
| Supply Voltage Range | 1.7V–5.5V - supports direct interfacing with 1.8V, 2.5V, 3.3V, and 5V microcontrollers without level shifters |
| I²C Clock Frequency | Up to 1 MHz at VCC ≥ 2.5V - doubles throughput vs. 400 kHz devices for high-speed configuration updates |
| Page Write Buffer | 64 bytes - reduces I²C transaction count by up to 64× compared to byte-write mode, minimizing bus occupancy |
| Endurance & Retention | 1,000,000 write cycles and >200 years data retention - suitable for field-deployed equipment requiring long-term reliability |
| Operating Temperature | −40°C to +125°C (Extended grade) - qualified for under-hood automotive, industrial motor drives, and outdoor IoT nodes |
| Write Protection | Hardware WP pin - prevents accidental overwrites during power-up/down or firmware glitches without software intervention |
Pinout & Package
24FC256T-E/OT is housed in a 5-lead SOT-23 package (3.0 mm × 1.7 mm × 1.3 mm height), optimized for ultra-compact PCB layouts. Chip address pins A0/A1/A2 are not connected in this variant, simplifying routing and eliminating external pull-up/pull-down requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SCL) | Serial Clock Input | Asynchronous edge-triggered input synchronized to host MCU's I²C clock; requires external pull-up resistor (2 kΩ typical for 1 MHz) |
| 2 (VSS) | Ground Reference | Primary return path for all internal circuitry; must be connected to system ground plane with low-inductance trace |
| 3 (SDA) | Serial Data I/O | Bidirectional open-drain node - shared with other I²C devices; requires same pull-up as SCL and supports multi-master arbitration |
| 4 (VCC) | Power Supply | Single 1.7–5.5V supply powering EEPROM core, interface logic, and charge pump; bypass capacitor (0.1 µF) required adjacent to pin |
| 5 (WP) | Write-Protect Input | Active-high enable: tied to VCC disables all writes (reads unaffected); tied to VSS enables full read/write access |
Key Features
| Feature | Design Value |
|---|---|
| 1 MHz I²C Compatibility | Enables 2.5× faster configuration loading vs. 400 kHz EEPROMs - critical for boot-time parameter recovery in real-time systems |
| Schmitt-Trigger Inputs | Provides 50 mV hysteresis on SDA/SCL, rejecting noise spikes up to 50 ns - eliminates need for external RC filtering in electrically noisy environments |
| Self-Timed Write Cycle | Automatically manages internal erase/write timing (max 5 ms); host only needs ACK polling - no fixed delays or timer dependencies |
| Low-Power Operation | 1 µA standby current and 3 mA max write current extend battery life in always-on sensor nodes and portable diagnostics tools |
| ESD Robustness | ±4 kV HBM rating - withstands handling and board-level ESD events without latch-up or parametric shift |
Applications
| Industrial PLC Configuration Storage | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Storing calibrated sensor offsets, I/O mapping tables, and firmware revision flags across power cycles in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed via I²C during boot and runtime reconfiguration. Use Value: Guarantees deterministic startup behavior after brownouts; 125°C rating ensures reliability inside control cabinets near heat-generating components. |
Use Scenario: Retaining seat position memory, mirror angle settings, and lighting profiles in vehicle body control units. IC Role / Device Role / Timing Role: Persistent parameter store interfaced directly to 3.3V automotive microcontroller without voltage translation. Use Value: AEC-Q100 qualification and −40°C to +125°C operation ensure functional safety compliance in under-dash mounting locations. |
| Medical Diagnostic Device Calibration | Smart Energy Meter Firmware Parameters |
Use Scenario: Holding factory-calibrated ADC gain/offset coefficients and user-adjusted diagnostic thresholds in portable ultrasound or ECG analyzers. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage accessed during device self-test and measurement initialization. Use Value: Hardware WP pin prevents unauthorized modification of calibration data; >200-year retention meets medical device regulatory shelf-life requirements. |
Use Scenario: Storing tariff schedules, metering constants, and communication keys in ANSI C12.22-compliant smart electricity meters. IC Role / Device Role / Timing Role: Trusted configuration vault updated infrequently but requiring absolute write integrity during firmware upgrades. Use Value: 1 million endurance cycles support decades of utility-side firmware revisions; 1.7V min VCC enables operation during capacitor-backed brownout conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 24AA256T-I/OT | Max I²C speed limited to 400 kHz; operates down to 1.7V but lacks 1 MHz capability at 2.5–5.5V | Lower throughput acceptable in cost-sensitive consumer electronics where boot latency is non-critical | Select when 1 MHz speed is unnecessary and legacy 400 kHz bus timing must be preserved |
| AT24C256-SSHL-T | Same 256-Kbit capacity and 1.8–5.5V range, but rated only to +85°C (industrial grade), no AEC-Q100 qualification | Suitable for commercial-grade applications like point-of-sale terminals or home automation hubs | Choose for price-sensitive designs where extended temperature and automotive qualification are not required |
Compared with 24FC256T-E/OT, the 24AA256T-I/OT trades speed for broader legacy compatibility, while the AT24C256-SSHL-T offers lower cost at the expense of temperature range and automotive qualification - making 24FC256T-E/OT the optimal choice for high-reliability, high-throughput embedded systems.
Availability
24FC256T-E/OT is available at Aetrix Electronics and suitable for industrial PLC configuration storage, automotive body control modules, medical diagnostic calibration, and smart energy meter firmware parameter management requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 24FC256T-E/OT 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 Inc. is a leading provider of microcontrollers, analog devices, and memory solutions, serving automotive, industrial, and communications markets with high-reliability silicon and comprehensive development tools.
The 24FC256 belongs to Microchip's 24XX256 family of I²C EEPROMs, engineered specifically for low-voltage, high-speed nonvolatile storage in resource-constrained embedded systems demanding robustness and long-term data integrity.
FAQ
What is the maximum I²C clock frequency supported by the 24FC256T-E/OT?
The 24FC256T-E/OT supports up to 1 MHz I²C clock frequency when VCC is 2.5V or higher. At VCC between 1.7V and 2.5V, the maximum clock frequency drops to 400 kHz. This dual-speed capability allows the 24FC256T-E/OT to maintain high throughput in 3.3V/5V systems while remaining compatible with 1.8V interfaces where speed is constrained by supply voltage.
Does the 24FC256T-E/OT have hardware write protection, and how is it implemented?
Yes, the 24FC256T-E/OT includes a dedicated Write-Protect (WP) pin. When WP is tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. The WP state is sampled at the Stop bit of each write command, ensuring reliable protection even during partial bus transactions. This hardware mechanism prevents accidental overwrites without relying on software locks or status registers.
What package type is used for the 24FC256T-E/OT, and are address pins available?
The 24FC256T-E/OT uses a 5-lead SOT-23 package. Unlike larger variants (e.g., SOIC or TSSOP), the SOT-23 version has no connections for A0, A1, or A2 address pins - they are internally unconnected. This simplifies PCB layout and eliminates external pull-up/pull-down resistors, but limits bus addressing to a single device per I²C segment unless multiplexing is used.
How many write cycles can the 24FC256T-E/OT endure, and what is its data retention period?
The 24FC256T-E/OT guarantees a minimum of 1,000,000 erase/write cycles and greater than 200 years of data retention at +25°C. These specifications are validated per JEDEC standards and apply across the full operating temperature range (−40°C to +125°C). The endurance rating is specified per page, reflecting wear-leveling behavior inherent to its 64-byte page architecture.
Is the 24FC256T-E/OT qualified for automotive applications?
Yes, the 24FC256T-E/OT carries AEC-Q100 qualification for Grade 1 (−40°C to +125°C) and is rated for extended temperature operation. Its design includes enhanced ESD protection (>4 kV HBM), robust power supply rejection, and process controls aligned with automotive quality standards - making it suitable for use in body control modules, infotainment systems, and ADAS-related subsystems.
24FC256T-E/OT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 5ms
- Access Time:
- 400 ns
- Voltage - Supply:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
24FC256T-E/OT FAQ
1.How can I place an order for 24FC256T-E/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 24FC256T-E/OT 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 24FC256T-E/OT reliable?
The price and inventory of 24FC256T-E/OT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 24FC256T-E/OT is usually 5 days.
3.What payment methods are accepted for 24FC256T-E/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24FC256T-E/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24FC256T-E/OT?
24FC256T-E/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24FC256T-E/OT 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 24FC256T-E/OT?
For technical support, including 24FC256T-E/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24FC256T-E/OT requirements.
6.How does Aetrix verify that 24FC256T-E/OT is sourced from the original manufacturer or authorized distributors?
All 24FC256T-E/OT 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 24FC256T-E/OT meets industry standards.
7.What is the process for return or replacement of 24FC256T-E/OT?
All 24FC256T-E/OT units undergo pre-shipment inspection (PSI). If there is an issue with 24FC256T-E/OT, 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 24FC256T-E/OT part is unused and in its original packaging.
Return procedure for 24FC256T-E/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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