Microchip Technology 24CSM01-I/SM

Overview

24CSM01-I/SM from Microchip Technology is a 1-Mbit I²C serial EEPROM with integrated security register, ECC error correction, and high-speed 3.4 MHz interface. It operates from 1.7V to 5.5V, supports byte/page writes (up to 256 bytes), and features factory-programmed 128-bit serial number and user-lockable 256-byte ID page. Used in automotive infotainment calibration storage and industrial sensor configuration.

For engineers reviewing the 24CSM01-I/SM datasheet, 24CSM01-I/SM pinout, 24CSM01-I/SM application, or 24CSM01-I/SM equivalent, key selection criteria include I²C high-speed mode timing compliance, hardware/software write protection flexibility, ECC-enabled reliability for mission-critical data, and AEC-Q100 qualification for automotive deployment.

Technical Context

The 24CSM01-I/SM implements a dual-register architecture: a 1-Mbit main EEPROM array (131,072 × 8) and a separate 4-Kbit Security register containing read-only 128-bit serial number plus 256-byte programmable ID page. Its I²C interface supports four speed modes (100 kHz, 400 kHz, 1 MHz, and 3.4 MHz HS mode) with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and ground bounce.

Write protection is configurable via hardware WP pin or software-defined zone locking through the Configuration register, which can be permanently locked. Built-in ECC corrects single-bit errors per 4-byte read and latches correction events via the Error Correction State (ECS) bit - a design feature enabling field-reliable data integrity verification without external logic.

Key Specifications

Pinout & Package

24CSM01-I/SM is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with industry-standard 150-mil body width and 1.27 mm pitch. This package supports automated optical inspection (AOI), reflow soldering per J-STD-020, and is compatible with legacy PCB footprints used for 24Cxx-series EEPROMs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24CS128-SSHL-T and BR24G128FJ-WE2, the 24CSM01-I/SM uniquely combines AEC-Q100 qualification, factory-unique 128-bit ID, lockable security page, and ECC in a single 1-Mbit I²C EEPROM - making it the only option meeting full automotive Tier-1 calibration storage requirements.

Availability

24CSM01-I/SM is available at Aetrix Electronics and suitable for automotive infotainment calibration storage, industrial sensor configuration, medical device settings retention, and consumer appliance firmware parameter management requiring stable component supply across multi-year production lifecycles.

Supply support for 24CSM01-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 24CSM01-I/SM belongs to Microchip's CS-series serial EEPROM family, engineered specifically for automotive-grade reliability, cryptographic identity support, and seamless integration into safety-critical embedded systems requiring tamper-resistant configuration storage.

FAQ

What is the maximum I²C clock frequency supported by the 24CSM01-I/SM?

The 24CSM01-I/SM supports up to 3.4 MHz in High-Speed (HS) mode when VCC ≥ 2.5V and operating within the Industrial temperature range (-40°C to +85°C). At lower voltages (1.7V–2.5V) or Extended temperature range (-40°C to +125°C), the maximum clock frequency is limited to 1 MHz. This dual-speed capability allows designers to optimize between programming speed and voltage/thermal margin.

Does the 24CSM01-I/SM require external pull-up resistors on SDA and SCL lines?

Yes, the 24CSM01-I/SM requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Recommended values are 330 Ω for 3.4 MHz HS mode, 2 kΩ for 1 MHz, and 10 kΩ for 100 kHz operation. The exact value depends on bus capacitance and desired rise time - failure to install appropriate pull-ups will result in communication failure or intermittent ACK errors.

How does the Security register in the 24CSM01-I/SM differ from the main EEPROM array?

The Security register in the 24CSM01-I/SM is a physically separate 4-Kbit block distinct from the 1-Mbit main array. It contains a read-only 128-bit factory-programmed serial number (first 16 bytes) followed by a 256-byte user-programmable, lockable ID page. Unlike the main array, the ID page can be permanently write-protected via software sequence - ensuring critical identifiers remain immutable even if the WP pin is compromised.

Can the 24CSM01-I/SM be used in automotive applications requiring AEC-Q100 qualification?

Yes, the 24CSM01-I/SM is explicitly AEC-Q100 qualified (Grade 2) and rated for operation from -40°C to +105°C. Its qualification includes stress testing for temperature cycling, humidity bias, mechanical shock, and ESD - making it suitable for engine control modules, ADAS sensors, and infotainment systems deployed in passenger vehicles. The "I" suffix in 24CSM01-I/SM denotes Industrial temperature grade, aligned with AEC-Q100 Grade 2 requirements.

What happens during an internal write cycle when the 24CSM01-I/SM receives an I²C command?

During an internal write cycle (up to 5 ms), the 24CSM01-I/SM ignores all incoming I²C commands and does not generate ACK bits - effectively appearing as a disconnected device on the bus. Host firmware must implement timeout-based polling (e.g., sending repeated START + device address until ACK is received) to detect write completion. This behavior is inherent to the self-timed write architecture and applies uniformly across all 24CSM01-I/SM package variants.