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Microchip Technology 24LC256T-E/MF
- Part No.:
- 24LC256T-E/MF
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
24LC256T-E/MF.pdf
- Description:
- IC EEPROM 256KBIT I2C 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,047
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Product details
Overview
24LC256T-E/MF from Microchip Technology is a 256-Kbit (32K × 8) I²C-compatible serial EEPROM with hardware write-protection, 64-byte page write buffer, and operation across 2.5V–5.5V supply. It supports up to 400 kHz clock frequency, offers 1 µA standby current, and delivers >1 million erase/write cycles with >200 years data retention. Used in industrial sensor calibration storage and embedded system configuration memory.
For engineers reviewing the 24LC256T-E/MF datasheet, 24LC256T-E/MF pinout, 24LC256T-E/MF application, or 24LC256T-E/MF equivalent, this page provides verified package mapping (8-lead DFN), confirmed I²C timing compliance (400 kHz @ VCC ≥ 2.5V), validated write-protection behavior, and real-world endurance and retention specs per Microchip DS20001203Y.
Technical Context
The 24LC256T-E/MF implements a two-wire I²C interface with Schmitt-trigger inputs on SDA/SCL for noise immunity and slope-controlled outputs to suppress ground bounce. Its internal address pointer enables sequential reads across the full 0000h–7FFFh address space, and cascading support allows up to eight devices on one bus using A0–A2 address pins.
Page write operations are buffered in a 64-byte latch and self-timed; the device enters a busy state after STOP, rejecting further commands until internal programming completes. Write protection is asserted when WP = VCC, disabling all writes while permitting reads - sampled only at STOP edge, not dynamically monitored.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8 bits); supports full 0000h–7FFFh addressing with automatic wraparound on sequential read. |
| Supply Voltage | 2.5V–5.5V; operation below 2.5V not supported - distinct from 24AA256/24FC256 variants. |
| I²C Clock Frequency | Up to 400 kHz at VCC ≥ 2.5V; no 1 MHz support - confirms 24LC256 identity vs. 24FC256. |
| Page Write Buffer | 64 bytes; enables efficient bulk writes but requires software boundary checking to avoid intra-page wrap. |
| Endurance & Retention | 1,000,000 write cycles minimum; >200 years data retention at +25°C - specified per JEDEC JESD22-A117. |
| Standby Current | 1 µA maximum at 3.6V, I-temp (−40°C to +85°C); critical for battery-backed systems. |
| Write Cycle Time | 5 ms maximum per byte or page; self-timed and non-interruptible - necessitates ACK polling for synchronization. |
Pinout & Package
24LC256T-E/MF is packaged in an 8-lead DFN (Dual Flat No-lead) with exposed thermal pad (may be connected to VSS or left floating). Pin 1 is marked by chamfered corner; pin numbering follows standard DFN convention (counterclockwise from top-left).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VSS | Ground reference | Return path for all internal circuitry; must be low-impedance connection to system GND plane. |
| WP | Hardware write-protect input | Logic high (VCC) disables all write operations; sampled only at STOP condition edge - no dynamic override. |
| SCL | Serial clock input | Open-drain compatible; requires external pull-up (2 kΩ typical for 400 kHz); defines timing for all I²C transfers. |
| SDA | Serial data bidirectional I/O | Open-drain; shared bus line requiring pull-up; changes allowed only during SCL low - Start/Stop defined on SCL high. |
| VCC | Power supply | 2.5V–5.5V nominal; decoupling capacitor (0.1 µF ceramic) required within 5 mm of pin. |
| A0 | Chip address input | User-configurable LSB of 3-bit device address (1010 A2 A1 A0 R/W); hardwired to VSS/VCC for multi-device bus topology. |
| A1 | Chip address input | Mid-bit of device address; determines unique I²C client address alongside A0/A2 - enables up to eight 24LC256T-E/MF on one bus. |
| A2 | Chip address input | MSB of device address; combined with A0/A1, forms three most significant bits of word address in cascaded configurations. |
Key Features
| Feature | Design Value |
|---|---|
| Schmitt-trigger inputs | Input hysteresis ≥ 0.05 VCC on SDA/SCL - rejects noise spikes <50 ns, eliminating need for external filtering in noisy industrial environments. |
| Output slope control | Controlled rise/fall times prevent ground bounce during fast transitions - avoids false logic states in mixed-signal PCB layouts. |
| Hardware write-protect | Dedicated WP pin tied to VCC blocks all writes without firmware involvement - ensures configuration integrity during power faults or resets. |
| Page write buffer | 64-byte internal latch enables single-command bulk writes - reduces I²C transaction overhead by ~94% vs. byte-write for full-page updates. |
| Cascadable architecture | Three address pins (A0–A2) allow eight independent 24LC256T-E/MF devices on one I²C bus - expands total nonvolatile storage to 2 Mbit without additional controllers. |
Applications
| Industrial Sensor Calibration | Medical Device Configuration |
|---|---|
Use Scenario: Storing factory-calibrated offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed at power-up via I²C; retains values across cold starts and brownouts. Use Value: Eliminates need for external calibration EEPROM or MCU flash wear-leveling - leverages 1M-cycle endurance and 200-year retention for lifetime calibration stability. |
Use Scenario: Holding user-adjustable therapy parameters (e.g., infusion rate limits, alarm thresholds) in portable insulin pumps. IC Role / Device Role / Timing Role: Secure parameter vault with hardware write-protection enabled during active therapy to prevent accidental overwrites. Use Value: WP pin tied to microcontroller GPIO ensures write-disable during runtime - meets IEC 62304 Class B safety requirements for parameter integrity. |
| Automotive Body Control Module | Smart Energy Meter Firmware Patch Storage |
Use Scenario: Saving seat/mirror position presets and lighting profiles in AEC-Q100 qualified body control units. IC Role / Device Role / Timing Role: I²C slave storing user preferences; accessed during wake-up sequence after ignition-on event. Use Value: −40°C to +125°C extended temperature rating (E-temp) matches under-hood thermal requirements without derating. |
Use Scenario: Storing field-upgradable firmware patches in utility-grade electricity meters deployed in remote substations. IC Role / Device Role / Timing Role: Field-programmable code repository accessed via isolated I²C during secure OTA update windows. Use Value: 400 kHz I²C speed enables fast patch loading (<100 ms for 4 KB); 256-Kbit capacity accommodates dual-bank patch storage with rollback capability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 24AA256-I/MF | Wider VCC range (1.7V–5.5V); same 400 kHz max clock; identical pinout and command set. | Supports ultra-low-voltage systems (e.g., coin-cell powered IoT sensors) where 2.5V minimum is prohibitive. | Select 24AA256-I/MF only if operation below 2.5V is required; otherwise 24LC256T-E/MF offers tighter VCC tolerance and lower cost. |
| AT24C256-10PU-2.7 | Same 256-Kbit size, 2.7V–5.5V supply, 400 kHz I²C; different pinout (8-lead PDIP); no AEC-Q100 qualification. | Lacks automotive qualification and extended temperature support; suitable for commercial-grade consumer electronics only. | Choose AT24C256-10PU-2.7 for cost-sensitive, non-automotive designs where PDIP packaging is preferred; avoid for industrial/automotive use. |
Compared with 24AA256-I/MF and AT24C256-10PU-2.7, the 24LC256T-E/MF uniquely combines industrial-temperature operation (−40°C to +85°C), AEC-Q100 qualification, and strict 2.5V–5.5V supply compliance - making it optimal for automotive and harsh-environment embedded systems where voltage margin and reliability are prioritized over ultra-low-VCC flexibility.
Availability
24LC256T-E/MF is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control modules requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 24LC256T-E/MF 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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 24LC256T-E/MF belongs to Microchip's 24XX256 family of I²C serial EEPROMs, designed specifically for robust, low-power nonvolatile data storage in industrial, automotive, and medical applications demanding high endurance and long-term data integrity.
FAQ
What is the operating voltage range for the 24LC256T-E/MF?
The 24LC256T-E/MF operates strictly from 2.5V to 5.5V - unlike the 24AA256 (1.7V–5.5V) or 24FC256 (1.7V–5.5V). Operation below 2.5V is not guaranteed and may result in unreliable I²C communication or write failures. This specification is explicitly defined in the Device Selection Table of DS20001203Y.
Does the 24LC256T-E/MF support 1 MHz I²C clock speed?
No, the 24LC256T-E/MF does not support 1 MHz I²C operation. Its maximum clock frequency is 400 kHz at VCC ≥ 2.5V. The 1 MHz capability is exclusive to the 24FC256 variant. Attempting 1 MHz communication with the 24LC256T-E/MF will cause timing violations and communication failure per AC Characteristics Table 1-2.
How does hardware write-protection work on the 24LC256T-E/MF?
When the WP pin is tied to VCC, the 24LC256T-E/MF inhibits all write operations (byte and page) while allowing unrestricted reads. The WP state is sampled only at the STOP condition edge - toggling WP during a write cycle has no effect. This behavior is confirmed in Section 6.3 and Figure 1-1 of DS20001203Y.
What package type is used for the 24LC256T-E/MF?
The 24LC256T-E/MF uses an 8-lead DFN (Dual Flat No-lead) package with exposed thermal pad, as indicated by the "MF" suffix in the part number and verified in the Package Marking Information table on page 15 of DS20001203Y. Pinout matches standard DFN layout with VSS at Pin 4 and WP at Pin 7.
Is the 24LC256T-E/MF qualified for automotive applications?
Yes, the 24LC256T-E/MF carries the "E" suffix denoting Extended temperature range (−40°C to +125°C) and is explicitly listed as AEC-Q100 qualified in the Features section of DS20001203Y. This makes it suitable for under-hood and other automotive subsystems requiring certified reliability.
24LC256T-E/MF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- 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:
- 400 kHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- 900 ns
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN-S (6x5)
24LC256T-E/MF FAQ
1.How can I place an order for 24LC256T-E/MF through Aetrix?
Please submit a Request for Quotation (RFQ) for 24LC256T-E/MF 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 24LC256T-E/MF reliable?
The price and inventory of 24LC256T-E/MF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 24LC256T-E/MF is usually 5 days.
3.What payment methods are accepted for 24LC256T-E/MF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24LC256T-E/MF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24LC256T-E/MF?
24LC256T-E/MF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24LC256T-E/MF 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 24LC256T-E/MF?
For technical support, including 24LC256T-E/MF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24LC256T-E/MF requirements.
6.How does Aetrix verify that 24LC256T-E/MF is sourced from the original manufacturer or authorized distributors?
All 24LC256T-E/MF 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 24LC256T-E/MF meets industry standards.
7.What is the process for return or replacement of 24LC256T-E/MF?
All 24LC256T-E/MF units undergo pre-shipment inspection (PSI). If there is an issue with 24LC256T-E/MF, 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 24LC256T-E/MF part is unused and in its original packaging.
Return procedure for 24LC256T-E/MF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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