25CSM04T-I/CS0668

Overview

The Microchip Technology 25CSM04T-I/CS0668 is a 4-Mbit SPI serial EEPROM organized as 524,288 x 8 bits. 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 built-in security register with a preprogrammed 128-bit serial number and 256 bytes of user-programmable lockable ID page. It includes ECC logic for data integrity and configurable write protection schemes. The component is housed in an 8-ball CSP package and functions across industrial temperatures from -40°C to +85°C.

Feature Summary

• Integrated security register containing a factory-programmed 128-bit unique serial number and a 256-byte user-programmable lockable ID page.
• Built-in Error Correction Code (ECC) logic capable of correcting single-bit errors within four-byte read sequences.
• Configurable write protection supporting both legacy block protection modes and enhanced user-definable memory partitioning.
• Supports JEDEC standard Manufacturer Read ID for electronic device identification and system integration.

Applications

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

Procurement Notes

Verify the specific ordering suffix CS0668 corresponds to the 8-ball CSP package variant when sourcing. Confirm that the Industrial temperature grade (-40°C to +85°C) meets your operational environment requirements. Ensure the SPI interface timing parameters align with your host controller's capabilities. Check for any specific RoHS compliance documentation required for your region. Validate that the power supply voltage remains within the specified 2.5V to 5.5V range during operation.

Selection Notes

Select this component if your design requires a 4-Mbit capacity with integrated hardware security features like unique serialization. Consider the 8-ball CSP package only if board space constraints necessitate a small footprint. Evaluate the need for ECC if your application involves high reliability or noisy environments. Compare against other Microchip EEPROMs if different interface types or capacities are suitable for your system architecture.

Part Context

The 25CSM04 belongs to Microchip's CS series of Serial EEPROMs, which are optimized for consumer and industrial markets. This series emphasizes reliability through features like ECC and robust write protection. The T-I/CS0668 designation indicates the tape-and-reel packaging, industrial temperature rating, and CSP package type. It complements Microchip's broader portfolio of memory solutions designed for embedded systems.

Replacement Considerations

Consult official Microchip documentation for verified cross-reference part numbers. Ensure any substitute maintains compatibility with SPI Mode 0 and 3 protocols. Verify that alternative components support the required 2.5V to 5.5V operating voltage range. Confirm that replacement parts offer equivalent security features if serialization is critical to your application.

FAQ

How does the ECC feature improve data reliability?

The built-in ECC logic can correct up to one incorrectly read bit within every four bytes retrieved from the memory array, enhancing data integrity during read operations.

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

Legacy mode uses Block Protect bits in the STATUS register to protect quarters, halves, or the entire array. Enhanced mode allows users to define independent memory partitions with unique protection behaviors using Memory Partition Registers.

Can the user-programmable section of the Security Register be modified after locking?

No, once the user-programmable lockable ID page is permanently write-protected via a software sequence, it cannot be altered again.