25CSM04-I/MF

Overview

The Microchip Technology 25CSM04-I/MF is a 4-Mbit (524,288 x 8) SPI Serial EEPROM housed in an 8-pad TDFN package. It operates within a voltage range of 2.5V to 5.5V and supports clock frequencies up to 8 MHz at VCC ≥ 3.0V or 5 MHz at VCC ≥ 2.5V. The device features a 256-byte page size, self-timed write cycles with a maximum duration of 5 ms, and standby current as low as 1.0 µA at 2.5V. It includes built-in ECC logic for data integrity, a preprogrammed 128-bit serial number, and user-programmable lockable ID pages.

Feature Summary

• Integrated Error Correction Code (ECC) logic capable of correcting single-bit errors within four-byte read sequences to enhance data reliability.
• Configurable write protection schemes supporting both Legacy Block Protection and Enhanced Write Protection with user-definable memory partitions.
• Security register containing a factory-programmed unique 128-bit serial number and a 256-byte user-programmable lockable ID page.
• Supports JEDEC standard Manufacturer Read ID functionality for electronic device identification and verification.

Applications

• Consumer electronics requiring reliable nonvolatile storage
• Industrial applications demanding dependable data retention
• Medical devices needing secure configuration storage

Procurement Notes

Verify the specific suffix 'I/MF' corresponds to the Industrial temperature range (-40°C to +85°C) and the 8-pad TDFN package type. Confirm that the required voltage levels align with the specified 2.5V to 5.5V operating range. Ensure the design accommodates the SPI interface timing requirements, particularly the clock frequency limits relative to supply voltage. Check for any specific handling precautions associated with the TDFN package format during assembly.

Selection Notes

Select this component when a 4-Mbit capacity is required alongside robust security features such as unique serialization and configurable write protection. It is suitable for designs needing high endurance and long data retention without external error correction circuitry. Consider the TDFN package if space constraints favor a compact surface-mount solution over SOIC or CSP options. Ensure the host controller supports the necessary SPI modes and instruction set for full feature utilization.

Part Context

The 25CSM04 belongs to Microchip's 25CSM series of SPI Serial EEPROMs, which are optimized for applications requiring high reliability and security. This series integrates advanced features like ECC and enhanced write protection into a compact footprint. The 25CSM04 specifically offers 4 Mbits of storage, distinguishing it from smaller capacity variants while maintaining compatibility with standard SPI interfaces and similar pinouts across the family.

Replacement Considerations

Consult official Microchip documentation for verified cross-reference part numbers. Ensure any substitute maintains the same 4-Mbit capacity, SPI interface, and TDFN-8 package. Verify that replacement components support the required industrial temperature range and voltage specifications.

FAQ

How does the built-in ECC logic function?

The ECC logic can correct up to one incorrectly read bit within every four bytes read out from the memory array. It also provides a status flag in the STATUS register to indicate if errors were detected and corrected during the most recent read sequence.

What is the difference between Legacy and Enhanced Write Protection modes?

Legacy mode uses Block Protect bits in the STATUS register to protect quarter, half, or the entire memory array. Enhanced mode allows the user to define independent memory partitions via Memory Partition Registers, each with unique protection behaviors such as software or hardware write protection.