Microchip Technology 24CSM01T-E/Q4B

Overview

24CSM01T-E/Q4B from Microchip Technology is a 1-Mbit I²C serial EEPROM with AEC-Q100 automotive qualification, 3.4 MHz high-speed mode support, built-in ECC for single-bit error correction, and a factory-programmed 128-bit unique serial number. It operates from 1.7V to 5.5V across –40°C to +125°C and features dual write protection-hardware WP pin and software-configurable zone locking via Configuration register-for use in automotive control modules, industrial sensor calibration storage, and secure boot configuration.

For engineers reviewing the 24CSM01T-E/Q4B datasheet, 24CSM01T-E/Q4B pinout, 24CSM01T-E/Q4B application, or 24CSM01T-E/Q4B equivalent, key selection considerations include its extended temperature grade (–40°C to +125°C), wettable flank VDFN-8 package compatibility with automated optical inspection, 256-byte lockable ID page in Security register, and I²C Manufacturer ID command for system-level device enumeration.

Technical Context

The 24CSM01T-E/Q4B implements a two-wire I²C interface with hardware address inputs A1/A2 enabling up to four devices on one bus, and supports legacy and enhanced software write protection modes via a programmable Configuration register. Its memory is organized as 512 pages × 256 bytes, with dedicated 4-Kbit Security register containing read-only 128-bit serial number (0800h–080Fh) and user-lockable 256-byte ID page (0900h–090Fh).

It integrates on-chip high-voltage generation for EEPROM programming, Power-on Reset (POR) with 100 µs TPUP delay, and Schmitt-trigger SDA/SCL inputs with 50 mV hysteresis (VCC ≥ 2.5 V) for noise immunity. The Error Correction State (ECS) latch in the Configuration register flags when ECC has corrected a read error, enabling runtime reliability monitoring.

Key Specifications

Pinout & Package

24CSM01T-E/Q4B is packaged in an 8-lead Wettable Flank VDFN (Very Thin Dual Flat No-lead) with exposed thermal pad, optimized for automated optical inspection (AOI) and solder joint reliability in automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with AT24CS128-MAHM-T and BR24G128FJ-WE2, the 24CSM01T-E/Q4B delivers 8× higher density, AEC-Q100 qualification, ECC-based reliability, and cryptographic-grade security features - making it the sole option for new automotive and safety-critical embedded designs requiring guaranteed data integrity and device identity.

Availability

24CSM01T-E/Q4B is available at Aetrix Electronics and suitable for automotive ECU programming, industrial sensor calibration storage, and medical device parameter archiving requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for 24CSM01T-E/Q4B 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 microcontrollers, analog, FPGA, and memory solutions, serving automotive, industrial, communications, and consumer markets with vertically integrated silicon and development tools.

The 24CSM01T-E/Q4B belongs to Microchip's CS-series automotive EEPROM family, designed specifically for mission-critical nonvolatile storage in harsh environments where data integrity, traceability, and long-term reliability are mandatory - not merely desirable.

FAQ

What is the package type and lead count of the 24CSM01T-E/Q4B?

The 24CSM01T-E/Q4B uses an 8-lead Wettable Flank VDFN (Very Thin Dual Flat No-lead) package with exposed thermal pad. This package supports automated optical inspection (AOI) and improves solder joint reliability in automotive PCB assemblies. Pin count is fixed at 8, matching the functional I/O requirements of the I²C interface, address inputs, power, and write-protect control.

Does the 24CSM01T-E/Q4B support high-speed I²C mode, and what is the maximum clock frequency?

Yes, the 24CSM01T-E/Q4B supports I²C High-Speed mode up to 3.4 MHz when VCC is 2.5 V or higher and ambient temperature is within the Industrial range (–40°C to +85°C). At extended temperature (–40°C to +125°C), the maximum supported frequency remains 3.4 MHz per AEC-Q100 test conditions. This enables faster configuration loading in automotive ECUs compared to standard 400 kHz EEPROMs.

How does the built-in ECC function in the 24CSM01T-E/Q4B, and how is it monitored?

The 24CSM01T-E/Q4B implements on-die ECC that corrects up to one bit error per four-byte read. When correction occurs, the Error Correction State (ECS) latch in the Configuration register is set and remains asserted until cleared by host software. This allows real-time detection of memory degradation events - critical for predictive maintenance in automotive and industrial systems using the 24CSM01T-E/Q4B.

What is the purpose and structure of the Security register in the 24CSM01T-E/Q4B?

The Security register in the 24CSM01T-E/Q4B is a 4-Kbit dedicated area separate from main EEPROM. It contains a read-only 128-bit factory serial number (0800h–080Fh) and a user-programmable, permanently lockable 256-byte ID page (0900h–090Fh). Once locked, the ID page becomes immutable - ideal for storing cryptographic keys or calibration signatures that must survive field updates and counterfeiting attempts.

Can the 24CSM01T-E/Q4B be used in systems requiring AEC-Q100 compliance, and which stress test grades does it meet?

Yes, the 24CSM01T-E/Q4B is explicitly AEC-Q100 qualified for Grade 1 (–40°C to +125°C) and meets all applicable stress tests including HTOL, TCT, ESD-HBM (>4 kV), and mechanical shock. Its extended temperature rating, wettable flank VDFN package, and automotive-grade screening make it suitable for under-hood and transmission-control applications where the 24CSM01T-E/Q4B replaces legacy EEPROMs lacking formal qualification.