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Microchip Technology 24CS256T-I/SM
- Part No.:
- 24CS256T-I/SM
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
24CS256T-I/SM.pdf
- Description:
- IC EEPROM 256KBIT I2C 8SOIJ
- Quantity:
- Payment:
- Shipping:
Inventory:2,668
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Product details
Overview
24CS256T-I/SM from Microchip Technology is a 256-Kbit I²C serial EEPROM organized as 32,768 × 8-bit, supporting high-speed mode up to 3.4 MHz, 1.7V–5.5V operation, and built-in ECC for single-bit error correction. It integrates a factory-programmed 128-bit serial number and user-lockable 64-byte ID page, used in automotive infotainment storage, industrial sensor calibration data retention, and embedded system configuration backup.
For engineers reviewing the 24CS256T-I/SM datasheet, 24CS256T-I/SM pinout, 24CS256T-I/SM application, or 24CS256T-I/SM equivalent, key selection considerations include its AEC-Q100 qualification, dual write-protection modes (hardware WP pin + software-configurable zone protection), 1 µA standby current at 5.5V, and support for up to eight devices on a shared I²C bus with hardware address pins A0–A2.
Technical Context
The 24CS256T-I/SM implements a two-wire I²C interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and ground bounce. Its memory architecture comprises a 256-Kbit main array (0000h–7FFFh) and a separate 1-Kbit security register containing a read-only 128-bit serial number (0800h–080Fh) plus a user-programmable, lockable 64-byte ID page (0840h–087Fh).
Device behavior is modulated via a configurable register enabling either legacy full-array hardware write protection or enhanced software-defined protection across eight independent 32-Kbit zones. An Error Correction State (ECS) latch reports ECC invocation, and the device supports I²C Manufacturer ID commands returning a unique 24-bit identifier.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbits (32,768 × 8-bit), organized in 512 pages of 64 bytes each - enables efficient bulk writes without crossing page boundaries. |
| I²C Speed Modes | Up to 3.4 MHz High-Speed mode (2.5V–5.5V, Industrial temp); also supports 1 MHz, 400 kHz, and 100 kHz - ensures compatibility with legacy and high-throughput controllers. |
| Write Cycle Time | ≤5 ms max self-timed byte/page write - eliminates need for external timing control; internal ECC activation does not extend this time. |
| Voltage Range | 1.7V to 5.5V supply - supports direct interfacing with 1.8V, 3.3V, and 5V microcontrollers without level shifters. |
| Reliability | 1 million erase/write cycles; >200 years data retention at 55°C; ESD >4 kV - validated for automotive and industrial field lifetime requirements. |
| Security Features | Factory-programmed 128-bit globally unique serial number + 64-byte user-lockable ID page - eliminates manufacturing serialization overhead and enables secure device binding. |
| Power Consumption | Standby current ≤1 µA at 5.5V (I-temp); read current ≤1 mA; write current ≤3 mA - suitable for battery-backed and energy-constrained systems. |
Pinout & Package
24CS256T-I/SM is packaged in an 8-lead SOIJ (Small Outline J-Bend) with wettable flank leads, optimized for automated optical inspection (AOI) and solder joint reliability in automotive PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0 | Hardware Device Address Input | LSB of 3-bit client address; hardwired to VSS or VCC to select one of eight possible I²C addresses on shared bus. |
| A1 | Hardware Device Address Input | Middle bit of 3-bit client address; determines unique I²C slave address alongside A0 and A2. |
| A2 | Hardware Device Address Input | MSB of 3-bit client address; enables multi-drop topology with up to eight identical 24CS256T-I/SM devices. |
| VSS | Ground Reference | Primary return path for all internal circuitry and I/O; must be low-impedance connection to system ground plane. |
| SDA | Serial Data Bidirectional Line | Open-drain I²C data line requiring external pull-up; transmits/receives device address, word address, and data bytes. |
| VCC | Power Supply Input | 1.7V–5.5V supply; must ramp monotonically at ≤0.1 V/µs during power-up to ensure reliable POR behavior. |
| WP | Hardware Write-Protect Control | Active-high pin: tied to VCC disables all writes to main array and security register; tied to VSS enables writes. |
| SCL | Serial Clock Input | Input-only I²C clock line synchronized to host controller; rise/fall times constrained per AC specs to maintain timing margins. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated ECC Logic | Corrects up to one bit error per four-byte readout and sets ECS latch - improves functional safety compliance without host-side correction logic. |
| Dual Write-Protection Modes | Hardware WP pin for full-array lock + software-configurable Configuration register for per-zone (32-Kbit) protection - enables flexible security policies across boot code, calibration, and user data partitions. |
| 128-Bit Factory Serial Number | Globally unique, read-only value preprogrammed at wafer test - eliminates post-manufacturing serialization cost and enables traceability in Tier-1 automotive supply chains. |
| I²C Manufacturer ID Support | Returns unique 24-bit identifier via standardized command - allows runtime identification and firmware validation of genuine Microchip 24CS256T-I/SM devices. |
| AEC-Q100 Qualified | Qualified for Automotive Grade 2 (-40°C to +105°C) and extended Industrial (-40°C to +125°C) temperature ranges - meets stress testing requirements for under-hood and ADAS applications. |
Applications
| Automotive Infotainment | Industrial Sensor Calibration |
|---|---|
Use Scenario: Storing display brightness profiles, audio equalizer presets, and Bluetooth pairing history in vehicle head units. IC Role / Device Role / Timing Role: Nonvolatile configuration storage with guaranteed data integrity over 15+ year vehicle lifecycle. Use Value: Factory-programmed 128-bit serial number enables secure OTA update authentication; ECC prevents silent corruption of user preferences. | Use Scenario: Retaining calibrated offset/gain coefficients for pressure, temperature, and current sensors in PLC modules. IC Role / Device Role / Timing Role: High-reliability parameter storage accessible via standard I²C during sensor initialization or field recalibration. Use Value: 1 million write cycles support frequent recalibration; software zone protection isolates factory calibration data from field updates. |
| Embedded System Boot Config | Medical Device Settings Backup |
Use Scenario: Holding bootloader configuration flags, network MAC address, and secure boot keys in edge gateway devices. IC Role / Device Role / Timing Role: Secure, low-power persistent storage accessed early in boot sequence before DRAM initialization. Use Value: 1.7V minimum VCC allows operation during brown-out conditions; WP pin prevents accidental overwrite during firmware updates. | Use Scenario: Preserving user-adjusted therapy parameters and device usage logs in portable insulin pumps and infusion controllers. IC Role / Device Role / Timing Role: Safety-critical nonvolatile memory with verified data retention >200 years and AEC-Q100-grade reliability. Use Value: Lockable 64-byte ID page stores cryptographic keys; ECC ensures integrity of dosage history records for regulatory audit trails. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT24C256C-SSHL-T | No built-in ECC; no 128-bit serial number; only hardware WP protection; max I²C speed 1 MHz. | Lacks automotive-grade reliability features and secure device identity - suitable for cost-sensitive consumer electronics where ECC and serialization are unnecessary. | Select only if AEC-Q100 qualification, ECC, or factory serial number are not required. |
| 24AA256-I/SN | Same pinout but no Security register; no Manufacturer ID support; no High-Speed mode (>1 MHz); 100k write cycles vs. 1M. | Lower endurance and missing security features limit use to non-critical, low-volume industrial controls without traceability needs. | Choose only for legacy designs already using 24AA256 and where upgrade path to enhanced security is not mandated. |
Compared with AT24C256C-SSHL-T and 24AA256-I/SN, the 24CS256T-I/SM delivers higher reliability (1M cycles, ECC), stronger security (serial number + lockable ID), and broader voltage/speed capability - making it the only option qualified for automotive and safety-critical medical applications.
Availability
24CS256T-I/SM is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor calibration modules, and medical device settings backup requiring stable component supply across extended product lifecycles.
Supply support for 24CS256T-I/SM 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 design and manufacturing operations.
The 24CS256T-I/SM belongs to Microchip's CS-series serial EEPROM family, designed specifically for automotive, industrial, and medical applications demanding AEC-Q100 qualification, enhanced data integrity, and secure device identity.
FAQ
What is the operating voltage range of the 24CS256T-I/SM?
The 24CS256T-I/SM operates from 1.7V to 5.5V, enabling direct interface with 1.8V, 3.3V, and 5V microcontrollers without level-shifting circuitry. This wide range supports brown-out resilience in battery-powered systems and simplifies mixed-voltage board design. The device maintains full I²C functionality-including High-Speed mode-at all voltages within this range.
Does the 24CS256T-I/SM support I²C High-Speed mode, and what is the maximum frequency?
Yes, the 24CS256T-I/SM supports I²C High-Speed mode up to 3.4 MHz when VCC is 2.5V–5.5V and ambient temperature is within the Industrial range (−40°C to +85°C). At lower voltages (1.7V–2.5V), it operates at standard speeds up to 1 MHz. This dual-speed capability ensures backward compatibility while enabling faster configuration loading in performance-critical applications.
How does the built-in Error Correction Code (ECC) function in the 24CS256T-I/SM?
The 24CS256T-I/SM implements on-die ECC that detects and corrects single-bit errors within any four-byte read window. When correction occurs, the read-only Error Correction State (ECS) latch in the Configuration register is set, allowing host firmware to log or respond to latent errors. This hardware ECC eliminates the need for software-based checksums or redundant storage, improving system-level reliability and reducing MCU overhead.
What security features does the 24CS256T-I/SM provide beyond basic write protection?
Beyond the hardware WP pin, the 24CS256T-I/SM provides a factory-programmed 128-bit globally unique serial number, a user-programmable and permanently lockable 64-byte ID page, and a software-configurable Configuration register enabling per-zone (32-Kbit) write protection. These features support secure device authentication, tamper-resistant calibration storage, and flexible partitioning of sensitive vs. field-updatable data - critical for automotive and medical certifications.
Is the 24CS256T-I/SM AEC-Q100 qualified, and which grade does it meet?
Yes, the 24CS256T-I/SM is AEC-Q100 qualified for Automotive Grade 2 (−40°C to +105°C) and also rated for Extended Industrial temperature (−40°C to +125°C). This qualification covers stress tests including HTOL, TCT, ESD, and mechanical shock, confirming suitability for under-hood, ADAS, and infotainment applications where long-term reliability under thermal cycling and electrical noise is mandatory.
24CS256T-I/SM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- 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:
- 3.4 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- 70 ns
- Voltage - Supply:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIJ
24CS256T-I/SM FAQ
1.How can I place an order for 24CS256T-I/SM through Aetrix?
Please submit a Request for Quotation (RFQ) for 24CS256T-I/SM 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 24CS256T-I/SM reliable?
The price and inventory of 24CS256T-I/SM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 24CS256T-I/SM is usually 5 days.
3.What payment methods are accepted for 24CS256T-I/SM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 24CS256T-I/SM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 24CS256T-I/SM?
24CS256T-I/SM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 24CS256T-I/SM 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 24CS256T-I/SM?
For technical support, including 24CS256T-I/SM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 24CS256T-I/SM requirements.
6.How does Aetrix verify that 24CS256T-I/SM is sourced from the original manufacturer or authorized distributors?
All 24CS256T-I/SM 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 24CS256T-I/SM meets industry standards.
7.What is the process for return or replacement of 24CS256T-I/SM?
All 24CS256T-I/SM units undergo pre-shipment inspection (PSI). If there is an issue with 24CS256T-I/SM, 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 24CS256T-I/SM part is unused and in its original packaging.
Return procedure for 24CS256T-I/SM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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