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Microchip Technology 24CS256-E/MS
- Part No.:
- 24CS256-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
24CS256-E/MS.pdf
- Description:
- IC EEPROM 256KBIT I2C 1MHZ 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:400
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Product details
Overview
24CS256-E/MS from Microchip Technology is a 256-Kbit I²C serial EEPROM organized as 32,768 × 8-bit, supporting byte/page writes (up to 64 bytes), self-timed write cycles (≤5 ms), and high-speed I²C up to 3.4 MHz. It features a factory-programmed 128-bit serial number, user-lockable 64-byte ID page, built-in ECC for single-bit error correction, and hardware/software write protection - deployed in automotive infotainment control modules requiring tamper-resistant configuration storage.
For engineers reviewing the 24CS256-E/MS datasheet, 24CS256-E/MS pinout, 24CS256-E/MS application, or 24CS256-E/MS equivalent, key selection considerations include its AEC-Q100 qualification, extended temperature range (–40°C to +125°C), dual write-protection modes (WP pin + Configuration register), 1.7V–5.5V operating voltage, and compatibility with legacy 24AA256/24LC256 devices.
Technical Context
The 24CS256-E/MS implements a two-wire I²C interface with Schmitt-trigger inputs, slope-controlled outputs, and support for Standard (100 kHz), Fast (400 kHz), Fast Plus (1 MHz), and High-Speed (3.4 MHz) modes. Its memory architecture comprises a 256-Kbit main array (0000h–7FFFh) and a separate 1-Kbit Security register (0800h–087Fh), including read-only 128-bit serial number (0800h–080Fh) and programmable lockable ID page (0840h–087Fh).
Device operation is governed by three registers: Configuration register (enables enhanced zone-based software write protection across eight 32-Kbit zones), Security register (supports irreversible locking of user data), and Manufacturer ID register (24-bit I²C-compliant identifier). Built-in ECC corrects one bit per four-byte read, with an Error Correction State (ECS) latch flagging correction events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8-bit), organized in 512 pages of 64 bytes each - enables efficient firmware parameter storage with page-aligned updates. |
| I²C Speed Support | Up to 3.4 MHz (High-Speed mode), plus 1 MHz / 400 kHz / 100 kHz - allows high-throughput configuration loading in time-critical automotive subsystems. |
| Write Cycle Time | ≤5 ms maximum (self-timed) - eliminates need for external polling or timeout management during nonvolatile writes. |
| Operating Voltage | 1.7 V to 5.5 V - supports direct interfacing with 1.8 V, 2.5 V, 3.3 V, and 5 V microcontrollers without level shifters. |
| Temperature Range | –40°C to +125°C (Extended grade) - qualified for under-hood and powertrain applications per AEC-Q100 Grade 1. |
| Data Retention | >200 years at 55°C - ensures long-term integrity of calibration data and security credentials over vehicle lifetime. |
| Endurance | 1,000,000 erase/write cycles - supports frequent runtime logging or dynamic parameter tuning in industrial controllers. |
Pinout & Package
24CS256-E/MS is supplied in an 8-lead MSOP package (3.0 mm × 4.9 mm, 0.65 mm pitch), optimized for space-constrained automotive PCBs with wettable flank leads for automated optical inspection (AOI).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Hardware Address Input | LSB of 3-bit device address; hardwired to VSS or VCC to select one of eight possible I²C addresses on shared bus. |
| A1 | Hardware Address Input | Middle bit of 3-bit device address; enables multi-device topology without address conflict in distributed sensor nodes. |
| A2 | Hardware Address Input | MSB of 3-bit device address; required to be logic '0' in SOT-23 variant but fully functional in MSOP for full address expansion. |
| VSS | Ground Reference | Primary return path for all internal circuitry; must be low-impedance connection to minimize noise coupling into I²C lines. |
| SDA | Serial Data Bidirectional Line | Open-drain I²C data line requiring external pull-up; supports bidirectional communication and ACK/NACK signaling per I²C protocol. |
| SCL | Serial Clock Input | Master-generated clock synchronizing all data transfers; includes Schmitt trigger input for robust noise immunity in electrically noisy environments. |
| WP | Hardware Write-Protect Input | Active-high pin disabling all writes to main array and Security register when tied to VCC - provides fail-safe protection during system boot. |
| VCC | Power Supply | Single supply rail (1.7–5.5 V); powers internal logic, EEPROM core, and I/O buffers - no separate VDD/VIO required. |
Key Features
| Feature | Design Value |
|---|---|
| Factory-Programmed 128-Bit Serial Number | Uniquely identifies each unit across CS-series EEPROMs - eliminates manufacturing serialization overhead in automotive ECU production. |
| Enhanced Software Write Protection | Configurable via locked Configuration register to protect any of eight independent 32-Kbit zones - enables granular access control for bootloader, calibration, and user data partitions. |
| Built-In ECC Logic | Corrects single-bit errors within any four-byte read window and latches error occurrence in ECS flag - improves data reliability without host-side error-handling firmware. |
| I²C Manufacturer Identification Function | Returns unique 24-bit ID on command - enables automatic device identification and firmware validation in multi-vendor BOMs. |
| AEC-Q100 Automotive Qualification | Qualified to Grade 1 (–40°C to +125°C) with full reliability testing - meets automotive functional safety requirements for non-safety-critical memory storage. |
Applications
| Automotive Body Control Module | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing door lock actuation history, mirror position presets, and lighting profiles across vehicle lifecycle. IC Role / Device Role / Timing Role: Nonvolatile configuration register holding user-customizable settings with tamper resistance and field-upgradable parameters. Use Value: Leverages 128-bit serial number for secure module binding and ECC for corruption-free retention over 15+ years of thermal cycling. |
Use Scenario: Persisting I/O mapping tables, PID tuning coefficients, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: High-reliability parameter store accessed via I²C during PLC startup and runtime reconfiguration. Use Value: 1M write cycles and >200-year data retention ensure uninterrupted operation across decades of maintenance cycles without memory replacement. |
| Medical Infusion Pump Calibration | Smart Energy Meter Firmware Parameters |
Use Scenario: Securing flow rate calibration constants, dose limits, and audit logs in Class II medical devices subject to FDA 21 CFR Part 11. IC Role / Device Role / Timing Role: Cryptographically isolated storage element with lockable ID page for regulatory traceability and anti-tampering. Use Value: User-programmable, permanently lockable 64-byte ID page stores digitally signed calibration certificates verifiable at boot. |
Use Scenario: Holding tariff schedules, metering constants, and communication keys in ANSI C12.22-compliant smart meters operating in outdoor substations. IC Role / Device Role / Timing Role: Extended-temperature EEPROM interfacing directly with 3.3 V metrology SoC over I²C at 1 MHz. Use Value: 1.7 V minimum VCC enables reliable operation during brownout conditions; WP pin provides hardware-enforced write disable during firmware updates. |
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/MS | No Security register, no ECC, max I²C speed 400 kHz, only Industrial temp (–40°C to +85°C) | Lacks 128-bit serial number and zone-level software write protection - suitable for cost-sensitive consumer applications without security or extended temp needs. | Select when AEC-Q100, ECC, or extended temperature are not required and legacy compatibility suffices. |
| AT24C256C-SSHL-T | No Security register, no ECC, no High-Speed mode (max 1 MHz), no AEC-Q100 qualification | Offers identical 256-Kbit density and basic I²C interface but lacks automotive qualification and advanced reliability features. | Choose only for non-automotive industrial use where Microchip-specific features (e.g., Manufacturer ID, Config register) are unnecessary. |
Compared with 24AA256-I/MS and AT24C256C-SSHL-T, the 24CS256-E/MS delivers differentiated value through AEC-Q100 qualification, built-in ECC, 128-bit serialization, and configurable software write protection - making it the sole option among the three qualified for extended-temperature automotive and high-integrity industrial deployments.
Availability
24CS256-E/MS is available at Aetrix Electronics and suitable for automotive body control units, industrial PLCs, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature and long product lifecycles.
Supply support for 24CS256-E/MS 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with global design, manufacturing, and support infrastructure.
The 24CS256 belongs to Microchip's CS-series serial EEPROM family, engineered specifically for automotive and high-reliability industrial applications demanding enhanced security, extended temperature operation, and built-in data integrity mechanisms.
FAQ
What is the operating voltage range of the 24CS256-E/MS?
The 24CS256-E/MS operates from 1.7 V to 5.5 V, enabling direct interface with 1.8 V, 2.5 V, 3.3 V, and 5 V systems without level-shifting circuitry. This wide range supports mixed-voltage designs and brownout resilience in automotive and industrial environments where supply rails may fluctuate.
Does the 24CS256-E/MS support high-speed I²C mode?
Yes, the 24CS256-E/MS supports I²C High-Speed mode up to 3.4 MHz when VCC ≥ 2.5 V and operating in Industrial temperature range. This capability accelerates configuration loading in time-sensitive applications such as automotive ADAS sensor initialization and real-time industrial controller setup.
How does the Security register in the 24CS256-E/MS function?
The 24CS256-E/MS Security register contains a factory-programmed, globally unique 128-bit serial number (read-only, 0800h–080Fh) and a user-programmable, lockable 64-byte ID page (0840h–087Fh). Once locked via software sequence, the ID page becomes permanently read-only - ideal for storing cryptographic keys or calibration signatures.
What write protection options are available on the 24CS256-E/MS?
The 24CS256-E/MS offers dual write protection: hardware-based via the WP pin (disables all writes when high), and software-based via the Configuration register (enables independent protection of any of eight 32-Kbit zones). The Configuration register itself can be permanently locked to prevent further changes.
Is the 24CS256-E/MS AEC-Q100 qualified?
Yes, the 24CS256-E/MS is AEC-Q100 qualified for Grade 1 (–40°C to +125°C), with full stress testing including HTOL, TC, HAST, and ESD (>4 kV). This qualification validates its suitability for under-hood automotive applications such as engine control, transmission, and body electronics.
24CS256-E/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm 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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
24CS256-E/MS FAQ
1.How can I place an order for 24CS256-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 24CS256-E/MS 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 24CS256-E/MS reliable?
The price and inventory of 24CS256-E/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 24CS256-E/MS is usually 5 days.
3.What payment methods are accepted for 24CS256-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24CS256-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24CS256-E/MS?
24CS256-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24CS256-E/MS 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 24CS256-E/MS?
For technical support, including 24CS256-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24CS256-E/MS requirements.
6.How does Aetrix verify that 24CS256-E/MS is sourced from the original manufacturer or authorized distributors?
All 24CS256-E/MS 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 24CS256-E/MS meets industry standards.
7.What is the process for return or replacement of 24CS256-E/MS?
All 24CS256-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 24CS256-E/MS, 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 24CS256-E/MS part is unused and in its original packaging.
Return procedure for 24CS256-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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