25CS320-I/MS

Overview

The Microchip Technology 25CS320-I/MS is a 32-Kbit (4,096 x 8 bit) Serial EEPROM utilizing an SPI-compatible bus. It features a Security Register with a preprogrammed 128-bit serial number and a 32-byte user-programmable lockable ID page. The device includes built-in Error Correction Code (ECC) logic for data integrity and supports both Legacy and Enhanced Write Protection modes. Operating voltage ranges from 1.7V to 5.5V, with clock frequencies up to 20 MHz at VCC ≥ 4.5V. It is AEC-Q100 qualified and operates within the Industrial temperature range of -40°C to +85°C.

Feature Summary

• Integrated Security Register containing a factory-programmed 128-bit unique serial number and a 32-byte user-programmable lockable ID page.
• Built-in Error Correction Code (ECC) logic capable of correcting single-bit errors within four-byte readouts to enhance data reliability.
• Configurable write protection schemes supporting both Legacy Block Protection and Enhanced User-Definable Memory Partitioning.
• Programmable Undervoltage Lockout (UVLO) detection circuit that inhibits write sequences during brown-out events.

Applications

• Automotive systems requiring AEC-Q100 qualified nonvolatile memory storage
• Industrial applications needing reliable data retention and enhanced write protection
• Consumer electronics requiring component serialization via unique serial numbers

Procurement Notes

Verify the suffix 'I' confirms the Industrial temperature rating (-40°C to +85°C). Confirm the 'MS' suffix corresponds to the 8-Lead MSOP package. Ensure the specific revision matches the datasheet DS20006923B. Check for AEC-Q100 qualification requirements if deploying in automotive environments. Validate supply voltage compatibility with the 1.7V to 5.5V operating range.

Selection Notes

Select this component when a 32-Kbit EEPROM with integrated serialization and ECC is required. It is suitable for designs needing flexible write protection through partition registers or legacy block protection. Consider this part for SPI interfaces requiring operation across a wide voltage range. It is appropriate for industrial and automotive sectors demanding high reliability and long data retention.

Part Context

The 25CS320 belongs to Microchip's CS series of Serial EEPROMs. It is backward compatible with devices such as the 25AA320A, 25LC320A, and AT25320B. The device shares architectural similarities with other members of the family but offers distinct enhancements like the dedicated Security Register and configurable UVLO thresholds.

Replacement Considerations

The datasheet explicitly states backward compatibility with the 25AA320A, 25LC320A, and AT25320B. Verify pinout and electrical characteristics match before substitution. Ensure the replacement supports the required SPI modes and voltage levels.

FAQ

What is the function of the Security Register?

The Security Register contains a read-only section with a factory-programmed 128-bit unique serial number and a 32-byte user-programmable section that can be permanently locked for secure data storage.

How does the device handle undervoltage conditions?

The 25CS320 includes a programmable Undervoltage Lockout (UVLO) detection circuit. If the supply voltage drops below the configured threshold, all write sequences are inhibited to prevent data corruption.

What write protection modes are supported?

The device supports Legacy Write Protection mode using Block Protection bits and Enhanced Write Protection mode, which allows user-definable memory partitions with independent protection behaviors.