My Inquiry
My Account
Microchip Technology 24AA256-E/MF
- Part No.:
- 24AA256-E/MF
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
24AA256-E/MF.pdf
- Description:
- IC EEPROM 256KBIT I2C 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,632
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
24AA256-E/MF from Microchip Technology is a 256-Kbit I²C serial EEPROM with 32K × 8 organization, operating from 1.7V to 5.5V, supporting up to 400 kHz clock frequency, and rated for industrial temperature range (−40°C to +85°C). It features 64-byte page write buffer, hardware write-protection via WP pin, and >1 million erase/write cycles - deployed in embedded systems requiring nonvolatile parameter storage with low-voltage operation.
For engineers reviewing the 24AA256-E/MF datasheet, 24AA256-E/MF pinout, 24AA256-E/MF application, or 24AA256-E/MF equivalent, key selection considerations include VCC min (1.7V), I²C speed grade (400 kHz max at ≥2.5V), package-specific pin mapping (8-lead DFN), endurance (1M cycles), and WP-enabled hardware lock for firmware configuration data.
Technical Context
The 24AA256-E/MF implements a two-wire I²C-compatible interface with Schmitt-trigger inputs on SDA/SCL for noise immunity and slope-controlled outputs to suppress ground bounce. Its internal address pointer supports current-address, random, and sequential reads across the full 0000h–7FFFh memory space.
Write operations are self-timed: byte writes complete in ≤5 ms, and page writes (up to 64 bytes) also execute within 5 ms. Acknowledge polling is supported to detect write completion without fixed delay timing, enabling efficient bus utilization in real-time systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256 Kbit (32K × 8), providing sufficient space for calibration tables, device IDs, and configuration registers in resource-constrained microcontrollers. |
| VCC operating range | 1.7V to 5.5V - enables direct interfacing with 1.8V, 3.3V, and 5V logic domains without level-shifting. |
| Max I²C clock frequency | 400 kHz at VCC ≥ 2.5V; 100 kHz at 1.7V ≤ VCC < 2.5V - defines maximum throughput for parameter updates in battery-powered sensors. |
| Page write buffer | 64 bytes - allows burst programming of configuration blocks with single Stop condition, reducing I²C transaction overhead. |
| Endurance & retention | 1,000,000 erase/write cycles and >200 years data retention - ensures long-term reliability in field-deployed industrial controllers. |
| Write-protect method | Hardware pin (WP): tied to VCC disables all writes; tied to VSS enables full read/write access - provides tamper-resistant storage for critical settings. |
| Temperature range | Industrial (−40°C to +85°C) - qualified for use in automotive body control modules and industrial PLC I/O expanders. |
Pinout & Package
24AA256-E/MF is supplied in an 8-lead DFN (Dual Flat No-lead) package with exposed thermal pad, measuring 2 mm × 3 mm × 0.75 mm (MSL3, RoHS-compliant). Pin 1 is marked by chamfered corner; exposed pad may be connected to VSS or left floating per layout requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VSS | Ground reference | Primary return path for I²C signals and internal EEPROM core; must be low-impedance connection to system GND plane. |
| WP | Write-protect input | Active-high enable: logic high (VCC) locks entire memory array against accidental writes; logic low (VSS) permits full read/write access. |
| SCL | Serial clock input | Asynchronous master-generated clock; requires external pull-up resistor (2 kΩ typical for 400 kHz operation). |
| SDA | Serial data bidirectional I/O | Open-drain output; requires same pull-up as SCL; changes only during SCL low to avoid false Start/Stop detection. |
| VCC | Power supply | Supplies internal charge pump for EEPROM programming; decoupling capacitor (100 nF ceramic) required within 5 mm. |
| A0, A1, A2 | Chip address inputs | Set 3-bit device address (1010xxxA2A1A0); for DFN package, all three pins are functional and must be hardwired to VSS or VCC. |
Key Features
| Feature | Design Value |
|---|---|
| Schmitt-trigger inputs | Input hysteresis ≥0.05×VCC on SDA/SCL - rejects noise spikes up to 50 ns, eliminating need for external filtering in electrically noisy motor-control environments. |
| Output slope control | Controlled rise/fall times prevent ground bounce during fast I²C transitions - avoids corruption of adjacent digital signals on shared PCB layers. |
| Self-timed write cycle | No external timing components needed; internal timer guarantees ≤5 ms completion - simplifies firmware design versus fixed-delay polling. |
| 64-byte page buffer | Enables single-command writes of up to 64 bytes - reduces I²C bus arbitration overhead by ~90% compared to byte-by-byte writes. |
| Hardware write protection | WP pin assertion disables all write commands at silicon level - prevents firmware bugs or ESD events from corrupting factory-calibrated parameters. |
Applications
| Smart Energy Metering | Automotive Body Control Module |
|---|---|
|
Use Scenario: Storing tariff schedules, meter calibration coefficients, and tamper-event logs in utility-grade electricity meters. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed via I²C during boot and runtime; retains data through power loss and brownout conditions. Use Value: 1.7V operation ensures reliable writes during battery-backed backup mode; hardware WP prevents unauthorized firmware reconfiguration. |
Use Scenario: Saving seat position memory, mirror presets, and door-lock configuration in vehicle interior ECUs. IC Role / Device Role / Timing Role: Parameter storage peripheral interfaced to 8-bit/32-bit MCU over I²C; withstands automotive temperature cycling and vibration. Use Value: −40°C to +85°C rating and >1M endurance support 15+ year vehicle service life; 64-byte page writes accelerate user preference loading. |
| Industrial Sensor Transmitter | Medical Diagnostic Equipment |
|
Use Scenario: Holding sensor linearization tables, zero-offset compensation values, and calibration timestamps in 4–20 mA loop-powered transmitters. IC Role / Device Role / Timing Role: Low-power EEPROM co-located with analog front-end; accessed infrequently but must retain accuracy over decades. Use Value: 1 µA standby current extends battery life in wireless sensor nodes; >200-year data retention meets ISO 13849 functional safety requirements. |
Use Scenario: Storing patient-specific therapy parameters, device serial history, and regulatory compliance flags in portable ultrasound and infusion pumps. IC Role / Device Role / Timing Role: Secure configuration vault with hardware write-lock; accessed only during setup or maintenance mode. Use Value: WP pin physically prevents runtime modification of safety-critical settings; RoHS and AEC-Q100 qualification support medical regulatory submissions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 24LC256-I/MF | Requires minimum 2.5V VCC; identical pinout, timing, and memory map. | Not suitable for 1.8V systems; otherwise drop-in in 3.3V/5V designs with no layout change. | Select when system VCC is guaranteed ≥2.5V and cost sensitivity favors legacy part availability. |
| AT24C256-MAHM-T | Same 256-Kbit capacity, 1.8V–5.5V range, and 400 kHz speed; different manufacturer marking and JEDEC footprint. | Requires validation of WP behavior and ACK polling timing; not AEC-Q100 qualified. | Use where automotive qualification is not required and dual-sourcing is prioritized over guaranteed pin compatibility. |
Compared with 24LC256-I/MF, the 24AA256-E/MF enables lower-voltage operation critical for energy-harvesting sensors; versus AT24C256-MAHM-T, it offers certified automotive reliability and tighter DC/AC parameter guarantees across temperature.
Availability
24AA256-E/MF is available at Aetrix Electronics and suitable for smart metering, automotive body electronics, industrial sensor transmitters, and medical diagnostic equipment requiring stable component supply across extended product lifecycles.
Supply support for 24AA256-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, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.
The 24AA256 belongs to Microchip's serial EEPROM product line, engineered for robust, low-power nonvolatile storage in industrial, automotive, and consumer applications where data integrity and long-term reliability are essential.
FAQ
What is the minimum supply voltage required for reliable operation of the 24AA256-E/MF?
The 24AA256-E/MF operates reliably down to 1.7V across its full industrial temperature range. At VCC < 2.5V, maximum I²C clock frequency is limited to 100 kHz; above 2.5V, it supports up to 400 kHz. This 1.7V minimum enables integration into 1.8V microcontroller systems without level shifters, and ensures functionality during brownout conditions in battery-backed applications.
How does the WP pin function on the 24AA256-E/MF, and when is it sampled?
The WP (Write-Protect) pin on the 24AA256-E/MF is sampled at the Stop bit of each write command. When tied to VCC, it disables all write operations (byte and page) while permitting unrestricted reads; when tied to VSS, full read/write access is enabled. The pin state is latched only at Stop, so toggling WP mid-cycle has no effect - ensuring deterministic protection during firmware updates.
Can the 24AA256-E/MF perform page writes across memory boundaries, and what happens if it does?
No - the 24AA256-E/MF restricts page writes to within a single 64-byte physical page (e.g., addresses 0000h–003Fh). If a page write command attempts to cross a boundary (e.g., starting at 003Eh with 5 bytes), data wraps to the start of the same page, overwriting prior content. Application firmware must align page writes and validate address ranges to prevent unintended data loss.
What is the endurance specification for the 24AA256-E/MF, and how is it measured?
The 24AA256-E/MF is rated for 1,000,000 erase/write cycles at +25°C and 5.5V, specified per page (not per byte). Each page write - even of a single byte - triggers a full-page refresh, consuming one cycle from that page's endurance budget. This reflects real-world usage where partial updates still stress the entire 64-byte block, ensuring conservative lifetime estimation in field deployments.
Is the 24AA256-E/MF compatible with standard I²C protocol, and what clock speeds does it support?
Yes, the 24AA256-E/MF is fully I²C-bus compatible, supporting standard-mode (100 kHz), fast-mode (400 kHz), and fast-mode plus timing constraints. It uses 7-bit addressing with a base code of 1010b and three programmable chip-select bits (A2–A0), allowing up to eight devices on one bus. Its Schmitt-trigger inputs and slew-rate-limited outputs meet I²C electrical specifications across 1.7V–5.5V operation.
24AA256-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:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN-S (6x5)
24AA256-E/MF FAQ
1.How can I place an order for 24AA256-E/MF through Aetrix?
Please submit a Request for Quotation (RFQ) for 24AA256-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 24AA256-E/MF reliable?
The price and inventory of 24AA256-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 24AA256-E/MF is usually 5 days.
3.What payment methods are accepted for 24AA256-E/MF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24AA256-E/MF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24AA256-E/MF?
24AA256-E/MF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24AA256-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 24AA256-E/MF?
For technical support, including 24AA256-E/MF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24AA256-E/MF requirements.
6.How does Aetrix verify that 24AA256-E/MF is sourced from the original manufacturer or authorized distributors?
All 24AA256-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 24AA256-E/MF meets industry standards.
7.What is the process for return or replacement of 24AA256-E/MF?
All 24AA256-E/MF units undergo pre-shipment inspection (PSI). If there is an issue with 24AA256-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 24AA256-E/MF part is unused and in its original packaging.
Return procedure for 24AA256-E/MF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
24AA256-E/MF Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
