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Microchip Technology 24LC256-E/MF
- Part No.:
- 24LC256-E/MF
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
24LC256-E/MF.pdf
- Description:
- IC EEPROM 256KBIT I2C 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,201
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Product details
Overview
24LC256-E/MF from Microchip Technology is a 256-Kbit I²C serial EEPROM with 32K × 8 organization, operating from 2.5V to 5.5V, supporting up to 400 kHz clock frequency, and rated for industrial temperature range (−40°C to +85°C). It features hardware write-protection via the WP pin, 64-byte page write buffer, and Schmitt-trigger inputs for noise immunity - deployed in embedded systems requiring nonvolatile parameter storage with low-power I²C interface.
For engineers reviewing the 24LC256-E/MF datasheet, 24LC256-E/MF pinout, 24LC256-E/MF application, or 24LC256-E/MF equivalent, this page delivers verified electrical specs, package mapping to 8-lead DFN, validated I²C timing compliance (400 kHz @ VCC ≥ 2.5V), endurance (1M cycles), and real-world use context for industrial control, sensor calibration, and configuration retention.
Technical Context
The 24LC256-E/MF implements a two-wire I²C-compatible interface with open-drain SDA/SCL pins requiring external pull-ups, and uses internal address pointer logic for sequential reads across the full 0000h–7FFFh memory space. Its architecture includes a 64-byte page latch, self-timed erase/write cycle, and HV generator for EEPROM cell programming.
Chip addressing is controlled by A0–A2 inputs (hardwired or host-driven), enabling up to eight devices on one bus; for the /MF DFN package, all three address pins are functional and must be tied to VSS or VCC. Write protection is asserted when WP = VCC, disabling all writes while permitting reads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - provides sufficient nonvolatile storage for firmware parameters, calibration data, or device configuration in resource-constrained microcontrollers. |
| VCC Range | 2.5V to 5.5V - compatible with standard 3.3V and 5V logic domains without level shifting. |
| Max Clock Frequency | 400 kHz at VCC ≥ 2.5V - enables fast byte/page writes (≤5 ms) while maintaining robustness against bus noise in industrial environments. |
| Page Write Buffer | 64 bytes - allows efficient bulk writes without host intervention between bytes, reducing I²C transaction overhead. |
| Endurance | 1,000,000 erase/write cycles - supports frequent field updates (e.g., logging, counter rollover) over product lifetime. |
| Data Retention | 200 years at +25°C - ensures long-term reliability of stored settings without refresh in battery-backed or offline applications. |
| Write-Protect Logic | WP pin high = full array protection (0000h–7FFFh) - prevents accidental overwrites during power-up/down or firmware glitches. |
Pinout & Package
The 24LC256-E/MF is packaged in an 8-lead DFN (Dual Flat No-lead) with exposed thermal pad, footprint code MF per Microchip's packaging specification. Pin 1 is marked by chamfered corner; exposed pad may be connected to VSS or left floating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Chip Address Input | User-configurable LSB of 3-bit device address; must be hardwired to VSS or VCC to select one of eight possible I²C addresses on shared bus. |
| A1 | Chip Address Input | Middle bit of device address; determines unique client address alongside A0 and A2 for multi-device configurations. |
| A2 | Chip Address Input | MSB of device address; enables up to eight 24LC256-E/MF units on same I²C bus with distinct 7-bit addresses (1010xxx). |
| VSS | Ground | Reference node for all digital and analog circuitry; must be low-impedance connection to system ground plane. |
| SDA | Serial Data I/O | Open-drain bidirectional line for address/data transfer; requires external pull-up resistor (2 kΩ typical for 400 kHz operation). |
| SCL | Serial Clock Input | Input-only clock line synchronized to host controller; rising edge samples data, falling edge allows data change. |
| WP | Write-Protect Input | Active-high enable: logic high disables all write operations (byte/page) but permits unlimited reads - critical for safe boot-time access. |
| VCC | Power Supply | Primary supply rail (2.5–5.5V); decoupling capacitor (0.1 µF ceramic) required within 5 mm of pin for stable operation. |
Key Features
| Feature | Design Value |
|---|---|
| Schmitt-trigger inputs on SDA/SCL | 50 mV hysteresis (VHYS ≥ 0.05×VCC) - rejects noise spikes ≤50 ns, eliminating false Start/Stop detection in electrically noisy industrial enclosures. |
| Output slope control | Controlled SDA fall time (≤250 ns @ CB ≤100 pF) - suppresses ground bounce and EMI during high-speed transitions. |
| Self-timed write cycle | Maximum 5 ms per byte or page - frees host MCU from polling delay; ACK polling supported for precise completion detection. |
| Hardware write protection | Dedicated WP pin sampled at Stop condition - provides deterministic, glitch-immune protection independent of software state. |
| ESD robustness | >4000 V HBM - withstands handling and board-level electrostatic discharge without latch-up or parametric shift. |
Applications
| Industrial Sensor Node | Medical Device Calibration |
|---|---|
|
Use Scenario: Storing factory-calibrated offset/gain coefficients and user-adjusted thresholds in a portable blood glucose meter. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed at power-on reset via I²C; retains values across battery removal. Use Value: Eliminates need for external calibration hardware; enables field recalibration with traceable, tamper-resistant storage (WP pin secured during normal operation). |
Use Scenario: Holding patient-specific therapy parameters and usage history in an infusion pump with battery backup. IC Role / Device Role / Timing Role: Persistent data logger storing timestamped dose records and error logs using sequential write mode. Use Value: Achieves 200-year data retention at room temperature; 1M-cycle endurance supports daily log entries over 27+ years. |
| Smart Energy Meter | Automotive Body Control Module |
|
Use Scenario: Recording tariff schedules, billing cycles, and tamper events in a DIN-rail mounted electricity meter operating at 3.3V. IC Role / Device Role / Timing Role: I²C slave storing time-stamped kWh accumulation data; accessed by metering SoC during idle periods. Use Value: 400 kHz I²C interface enables rapid burst writes during zero-crossing intervals; 2.5V min VCC ensures operation during brown-out conditions. |
Use Scenario: Saving seat/mirror position presets and lighting profiles in a vehicle door module with CAN/LIN interface. IC Role / Device Role / Timing Role: Configuration memory mapped to microcontroller's I²C peripheral; read at startup to restore user preferences. Use Value: Hardware WP pin prevents corruption during ignition transients; industrial temp rating (−40°C to +85°C) matches under-hood requirements. |
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 (1.7–5.5V); identical pinout, timing, and memory map. | Supports 1.7V operation - suitable for ultra-low-power battery-powered sensors where 24LC256-E/MF cannot operate. | Select 24AA256-I/MF only if sub-2.5V supply is required; otherwise 24LC256-E/MF offers better noise margin at 2.5V+. |
| AT24C256-10PU-2.7 | Same 256-Kbit capacity, 400 kHz max, 2.7–5.5V VCC; different manufacturer (Microchip vs. Microchip-owned Atmel legacy part). | Legacy Atmel marking and packaging; identical functional behavior but distinct traceability and qualification documentation. | Use AT24C256-10PU-2.7 only for legacy design continuity; 24LC256-E/MF is preferred for new designs due to active Microchip support and extended temp validation. |
Compared with 24AA256-I/MF and AT24C256-10PU-2.7, the 24LC256-E/MF provides optimal trade-off of industrial temperature rating, proven 400 kHz I²C performance at 2.5V+, and direct Microchip technical support - making it ideal for cost-sensitive, volume industrial applications where 1.7V operation is unnecessary.
Availability
24LC256-E/MF is available at Aetrix Electronics and suitable for industrial sensor nodes, medical calibration storage, smart energy meters, and automotive body control modules requiring stable component supply across extended production lifecycles.
Supply support for 24LC256-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 microcontroller, mixed-signal, analog, and Flash-IP solutions, serving industrial, automotive, consumer, and communications markets with vertically integrated silicon and development tools.
The 24LC256-E/MF belongs to Microchip's 24XX256 family of I²C EEPROMs, designed specifically for reliable, low-power nonvolatile data storage in embedded systems where deterministic write timing, hardware write protection, and multi-device bus scalability are essential.
FAQ
What is the minimum supply voltage required for reliable operation of the 24LC256-E/MF?
The 24LC256-E/MF requires a minimum VCC of 2.5V for guaranteed functionality across its full industrial temperature range (−40°C to +85°C). Operation below 2.5V is not specified and may result in failed writes, invalid ACK responses, or unpredictable timing - unlike the 24AA256 variant, which supports down to 1.7V.
Does the 24LC256-E/MF support 1 MHz I²C communication?
No, the 24LC256-E/MF does not support 1 MHz I²C. Its maximum clock frequency is 400 kHz at VCC ≥ 2.5V. The 1 MHz capability is exclusive to the 24FC256 variant; attempting 1 MHz operation on the 24LC256-E/MF will cause timing violations and communication failure.
How many devices can be connected on the same I²C bus using the 24LC256-E/MF?
Up to eight 24LC256-E/MF devices can be connected on a single I²C bus using unique combinations of the A0, A1, and A2 address pins. Each device must have a distinct 3-bit chip address (1010xxx), and all pins must be hardwired to either VSS or VCC - floating address pins are not permitted.
What happens when the WP pin is held high during a write command to the 24LC256-E/MF?
When WP = VCC, the 24LC256-E/MF acknowledges the write command but performs no memory update - the internal write cycle is suppressed, no data is altered, and the device immediately accepts subsequent commands. This behavior ensures safe read-only access during critical boot sequences or firmware updates.
Is the 24LC256-E/MF pin-compatible with the 24AA256-I/MF in the MF package?
Yes, the 24LC256-E/MF and 24AA256-I/MF share identical 8-lead DFN (MF) package dimensions, pin numbering, and pin functions. Both support A0–A2 addressing, WP, SDA, SCL, VCC, and VSS on the same physical layout - enabling drop-in replacement where voltage and timing requirements align.
24LC256-E/MF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- Packaging:
- Tube
- 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)
24LC256-E/MF FAQ
1.How can I place an order for 24LC256-E/MF through Aetrix?
Please submit a Request for Quotation (RFQ) for 24LC256-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 24LC256-E/MF reliable?
The price and inventory of 24LC256-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 24LC256-E/MF is usually 5 days.
3.What payment methods are accepted for 24LC256-E/MF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24LC256-E/MF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24LC256-E/MF?
24LC256-E/MF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24LC256-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 24LC256-E/MF?
For technical support, including 24LC256-E/MF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24LC256-E/MF requirements.
6.How does Aetrix verify that 24LC256-E/MF is sourced from the original manufacturer or authorized distributors?
All 24LC256-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 24LC256-E/MF meets industry standards.
7.What is the process for return or replacement of 24LC256-E/MF?
All 24LC256-E/MF units undergo pre-shipment inspection (PSI). If there is an issue with 24LC256-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 24LC256-E/MF part is unused and in its original packaging.
Return procedure for 24LC256-E/MF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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