Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Memory > Memory

Microchip Technology 24FC256-E/ST16KVAO

Name: 24FC256-E/ST16KVAO
Brand: Microchip Technology
SKU: 24FC256-E/ST16KVAO
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 24FC256-E/ST16KVAO

Manufacturer:: Microchip Technology

Category:: Memory

Package:: 8-TSSOP (0.173", 4.40mm Width)

Datasheet:: 24FC256-E/ST16KVAO.pdf

Description:: IC EEPROM 256KBIT I2C 8TSSOP

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,538

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

24FC256-E/ST16KVAO from Microchip Technology is a 256-Kbit I²C serial EEPROM with 32K × 8 organization, 1.7V–5.5V single-supply operation, and 1 MHz maximum clock frequency at V_CC ≥ 2.5V. It features 64-byte page write buffer, hardware write-protect (WP), Schmitt-trigger inputs, and operates across –40°C to +125°C (Extended temperature range). It is used in automotive infotainment configuration storage and industrial sensor calibration data retention.

For engineers reviewing the 24FC256-E/ST16KVAO datasheet, 24FC256-E/ST16KVAO pinout, 24FC256-E/ST16KVAO application, or 24FC256-E/ST16KVAO equivalent, key selection criteria include its 1 MHz I²C speed at full voltage, extended-temp qualification (AEC-Q100), 64-byte page write capability, and SOIC-8 package with standard pinout compatible with legacy 24AA/24LC designs.

Technical Context

The 24FC256-E/ST16KVAO implements a two-wire I²C-compatible interface with programmable device addressing via A0–A2 pins, supporting up to eight devices on one bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic enabling self-timed erase/write cycles.

It supports byte and page write modes, random/sequential reads across the full 0000h–7FFFh address space, and uses acknowledge polling to detect write completion. The WP pin provides hardware-level protection of the entire 256-Kbit array when tied to V_CC, and Schmitt-trigger inputs on SDA/SCL ensure noise immunity in electrically noisy environments.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Size	256 Kbit (32K × 8) - supports firmware parameter tables, calibration coefficients, and event logs in resource-constrained systems.
Interface	I²C (Two-Wire Serial) - enables simple, low-pin-count connection to microcontrollers without dedicated parallel buses.
Max Clock Frequency	1 MHz at V_CC ≥ 2.5V - doubles throughput vs. 400 kHz parts, reducing write latency in high-frequency logging applications.
Page Write Buffer	64 bytes - allows efficient bulk writes (e.g., updating full sensor calibration sets) without 256 individual byte-write overhead.
Write Endurance	1,000,000 cycles - ensures reliable operation over 10+ years in cyclic data logging (e.g., battery management state-of-charge history).
Data Retention	200 years at +25°C - guarantees long-term integrity of factory-programmed identifiers, security keys, or device-specific tuning parameters.
Operating Temperature	–40°C to +125°C (Extended range) - qualified per AEC-Q100 Grade 1, suitable for under-hood automotive modules and industrial motor drives.
Supply Voltage	1.7V to 5.5V - interoperates with 1.8V, 3.3V, and 5V logic domains without level shifters in mixed-voltage systems.

Pinout & Package

24FC256-E/ST16KVAO is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package with 150-mil body width and standard JEDEC MS-012AC footprint. Pin 1 is marked with a beveled corner or dot; the package is RoHS-compliant and lead-free.

Pin/Terminal	Circuit Role	Design Meaning
A0	Chip Address Input	User-configurable LSB of 3-bit device address; 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 I²C client address when multiple 24FC256 devices share SDA/SCL lines.
A2	Chip Address Input	MSB of device address; enables cascading up to eight 24FC256-E/ST16KVAO units for 2-Mbit aggregate storage.
VSS	Ground Reference	Primary return path for all internal circuitry; must be connected to system ground plane with low-impedance trace.
SDA	Serial Data I/O	Open-drain bidirectional bus line; requires external pull-up resistor (2 kΩ typical for 1 MHz) to VCC for proper I²C signaling.
SCL	Serial Clock Input	Master-generated clock that synchronizes all read/write transfers; rising edge samples data, falling edge updates data.
WP	Write-Protect Control	Active-high hardware lock: tied to VCC disables all writes (reads remain functional); tied to VSS enables full read/write access.
VCC	Power Supply	Single 1.7–5.5V supply powering EEPROM core, interface logic, and charge pump; decoupling capacitor (100 nF) required near pin.

Key Features

Feature	Design Value
1 MHz I²C Compatibility	Enables faster configuration loading in real-time systems-e.g., boot-time parameter fetch completes in <1.5 ms for 64-byte page vs. ~6 ms at 400 kHz.
Schmitt Trigger Inputs	Provides 50 mV hysteresis on SDA/SCL, rejecting EMI-induced glitches in automotive or industrial noise environments without external filtering.
Self-Timed Write Cycle	Eliminates need for host MCU to manage timing delays; internal 5 ms max write cycle completes autonomously after STOP condition.
Hardware Write Protection	Prevents accidental or malicious firmware corruption by physically disabling writes-critical for safety-critical automotive ECUs and medical device calibration data.
AEC-Q100 Qualified	Validated for automotive use including temperature cycling, HTOL, and ESD testing-ensures reliability in engine control, ADAS, and body electronics modules.
64-Byte Page Write Buffer	Reduces I²C transaction count by 64× vs. byte writes, lowering bus arbitration overhead and improving system-level throughput in multi-master systems.

Applications

Automotive Infotainment Configuration Storage	Industrial Sensor Calibration Data Retention
Use Scenario: Storing user preferences (volume, EQ, display brightness), radio presets, and Bluetooth pairing IDs in head units and digital clusters. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed during boot and runtime via I²C; retains data across ignition cycles and power loss. Use Value: Enables personalized HMI experience without requiring backup batteries or supercapacitors-leverages 200-year data retention and AEC-Q100 qualification.	Use Scenario: Holding factory-calibrated offset/gain coefficients and linearization tables for pressure, temperature, and current sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Static parameter store read once at startup; updated only during factory calibration or field service using secure I²C commands. Use Value: Ensures measurement accuracy over lifetime; hardware WP prevents runtime corruption, and 1.7V operation supports brown-out resilience during mains dips.
Medical Device Usage Log Storage	Smart Energy Meter Firmware Parameter Backup
Use Scenario: Recording timestamped usage events (e.g., therapy session start/end, alarm triggers) in portable diagnostic equipment with regulatory audit requirements. IC Role / Device Role / Timing Role: Cyclic write buffer storing last 1000 events; overwritten in FIFO fashion using sequential page writes. Use Value: Meets IEC 62304 data integrity requirements; 1M endurance supports >10 years of daily logging at 300 events/day.	Use Scenario: Backing up tariff schedules, demand-response thresholds, and metering constants in ANSI C12.22-compliant smart meters deployed in harsh outdoor environments. IC Role / Device Role / Timing Role: Read-mostly storage updated quarterly via secure DLMS/COSEM; accessed during meter initialization and time-sync events. Use Value: Extended temperature range (–40°C to +125°C) ensures operation inside sealed meter enclosures exposed to desert heat or arctic cold.

Automotive Infotainment Configuration Storage

Industrial Sensor Calibration Data Retention

Use Scenario: Storing user preferences (volume, EQ, display brightness), radio presets, and Bluetooth pairing IDs in head units and digital clusters.

IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed during boot and runtime via I²C; retains data across ignition cycles and power loss.

Use Value: Enables personalized HMI experience without requiring backup batteries or supercapacitors-leverages 200-year data retention and AEC-Q100 qualification.

Use Scenario: Holding factory-calibrated offset/gain coefficients and linearization tables for pressure, temperature, and current sensors in PLC analog input modules.

IC Role / Device Role / Timing Role: Static parameter store read once at startup; updated only during factory calibration or field service using secure I²C commands.

Use Value: Ensures measurement accuracy over lifetime; hardware WP prevents runtime corruption, and 1.7V operation supports brown-out resilience during mains dips.

Medical Device Usage Log Storage

Smart Energy Meter Firmware Parameter Backup

Use Scenario: Recording timestamped usage events (e.g., therapy session start/end, alarm triggers) in portable diagnostic equipment with regulatory audit requirements.

IC Role / Device Role / Timing Role: Cyclic write buffer storing last 1000 events; overwritten in FIFO fashion using sequential page writes.

Use Value: Meets IEC 62304 data integrity requirements; 1M endurance supports >10 years of daily logging at 300 events/day.

Use Scenario: Backing up tariff schedules, demand-response thresholds, and metering constants in ANSI C12.22-compliant smart meters deployed in harsh outdoor environments.

IC Role / Device Role / Timing Role: Read-mostly storage updated quarterly via secure DLMS/COSEM; accessed during meter initialization and time-sync events.

Use Value: Extended temperature range (–40°C to +125°C) ensures operation inside sealed meter enclosures exposed to desert heat or arctic cold.

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/ST	Max I²C speed = 400 kHz; rated for Industrial (–40°C to +85°C), not Extended temp.	Lacks AEC-Q100 qualification and 125°C operation-unsuitable for under-hood automotive or high-ambient industrial use.	Select only if system clock budget permits slower I²C and ambient temperature stays ≤85°C.
AT24C256-10PU-2.7	Max I²C speed = 1 MHz but only at V_CC ≥ 2.7V; no AEC-Q100 qualification; endurance = 100K cycles (vs. 1M).	Lower write endurance and unqualified for automotive-requires revalidation for safety-critical logging.	Consider only for cost-sensitive consumer applications where 100K cycles suffice and temperature stays <85°C.

Compared with 24AA256-I/ST and AT24C256-10PU-2.7, the 24FC256-E/ST16KVAO delivers higher-speed communication, automotive-grade reliability, and tenfold greater endurance-making it the optimal choice for mission-critical, high-cycle, extended-temperature deployments.

Availability

24FC256-E/ST16KVAO is available at Aetrix Electronics and suitable for automotive infotainment, industrial sensor calibration, and medical device usage logging requiring stable component supply, long-lifecycle support, and AEC-Q100 compliance.

Supply support for 24FC256-E/ST16KVAO 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, serving automotive, industrial, communications, and consumer markets with vertically integrated silicon and development tools.

The 24FC256-E/ST16KVAO belongs to Microchip's 24XX256 family of I²C EEPROMs, designed specifically for robust, low-power nonvolatile data storage in electrically noisy, thermally demanding, and safety-critical embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the 24FC256-E/ST16KVAO?

The 24FC256-E/ST16KVAO supports up to 1 MHz I²C clock frequency when V_CC is 2.5V or higher. At V_CC < 2.5V, the maximum clock frequency drops to 400 kHz. This dual-speed capability allows designers to optimize bus performance while maintaining compatibility with low-voltage subsystems. The 24FC256-E/ST16KVAO datasheet specifies timing parameters like THIGH, TLOW, and TSU:DAT explicitly for both conditions.

Does the 24FC256-E/ST16KVAO require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC256-E/ST16KVAO requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. For 1 MHz operation, a 2 kΩ pull-up to V_CC is recommended; for 400 kHz, 2.2 kΩ is typical. The value must be selected based on bus capacitance and rise-time requirements per I²C specification. The 24FC256-E/ST16KVAO itself does not integrate pull-ups.

How does hardware write-protection work on the 24FC256-E/ST16KVAO?

Hardware write-protection on the 24FC256-E/ST16KVAO is controlled by the WP pin: when tied to V_CC, all write operations (byte and page) to the entire 256-Kbit array are inhibited, though read operations continue normally. The WP state is sampled at the STOP condition of each write command. The 24FC256-E/ST16KVAO ignores WP transitions during active writes-ensuring atomicity and preventing partial corruption.

Is the 24FC256-E/ST16KVAO AEC-Q100 qualified, and what grade does it meet?

Yes, the 24FC256-E/ST16KVAO is AEC-Q100 qualified for Grade 1 (–40°C to +125°C), as confirmed in Microchip's official documentation. This qualification covers stress tests including temperature cycling, high-temperature operating life (HTOL), and ESD (HBM >4 kV). It is certified for use in automotive powertrain, chassis, and infotainment systems-not just "automotive-grade" marketing language, but fully tested and documented compliance.

Can the 24FC256-E/ST16KVAO be used interchangeably with the 24AA256 or 24LC256 in existing designs?

The 24FC256-E/ST16KVAO shares identical pinout, command set, and memory organization with the 24AA256 and 24LC256, making it a drop-in replacement in most cases. However, its 1 MHz speed and extended temperature range may expose timing margins in legacy designs optimized for 400 kHz. Verify SCL rise/fall times and acknowledge polling behavior-especially under low-V_CC conditions-before substitution. The 24FC256-E/ST16KVAO is functionally backward compatible but not electrically identical in all operating corners.

24FC256-E/ST16KVAO Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-TSSOP (0.173", 4.40mm Width)

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:: 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:: 8-TSSOP

24FC256-E/ST16KVAO FAQ

1.How can I place an order for 24FC256-E/ST16KVAO through Aetrix?

Please submit a Request for Quotation (RFQ) for 24FC256-E/ST16KVAO 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 24FC256-E/ST16KVAO reliable?

The price and inventory of 24FC256-E/ST16KVAO are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 24FC256-E/ST16KVAO is usually 5 days.

3.What payment methods are accepted for 24FC256-E/ST16KVAO?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24FC256-E/ST16KVAO transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 24FC256-E/ST16KVAO?

24FC256-E/ST16KVAO orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 24FC256-E/ST16KVAO 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 24FC256-E/ST16KVAO?

For technical support, including 24FC256-E/ST16KVAO datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24FC256-E/ST16KVAO requirements.

6.How does Aetrix verify that 24FC256-E/ST16KVAO is sourced from the original manufacturer or authorized distributors?

All 24FC256-E/ST16KVAO 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 24FC256-E/ST16KVAO meets industry standards.

7.What is the process for return or replacement of 24FC256-E/ST16KVAO?

All 24FC256-E/ST16KVAO units undergo pre-shipment inspection (PSI). If there is an issue with 24FC256-E/ST16KVAO, 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 24FC256-E/ST16KVAO part is unused and in its original packaging.

Return procedure for 24FC256-E/ST16KVAO:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

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.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

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.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

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…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

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…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

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…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

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 …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

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…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

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…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

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…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

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…