25CS320T-I/ST

Overview

The Microchip Technology 25CS320T-I/ST is a 32-Kbit (4,096 x 8 bit) Serial EEPROM utilizing SPI compatible bus. It features a page size of 32 bytes and supports byte or sequential reads/writes with self-timed write cycles up to 4 ms maximum. Operating voltage ranges from 1.7V to 5.5V. The device includes a Security Register with a preprogrammed 128-bit serial number and 32-byte user-programmable ID page. Built-in ECC logic corrects single-bit errors within four-byte readouts. High-speed clock frequencies reach 20 MHz at VCC ≥ 4.5V, 10 MHz at VCC ≥ 2.5V, and 5 MHz at VCC ≥ 1.7V. It offers legacy block protection and enhanced user-definable memory partitioning. Undervoltage lockout detection protects against brown-out events.

Feature Summary

• Integrated Error Correction Code (ECC) logic for increased data reliability
• Configurable Enhanced Write Protection Mode with independent memory partitions
• Factory-programmed 128-bit unique serial number in nonvolatile Security Register
• Undervoltage Lockout Detection circuit to inhibit writes during power drops

Applications

• Automotive applications requiring AEC-Q100 qualification
• Industrial systems needing reliable nonvolatile memory storage
• Consumer electronics requiring hardware serialization

Procurement Notes

Verify the specific suffix 'I/ST' corresponds to Industrial temperature range (-40°C to +85°C) and TSSOP-8 tape and reel packaging. Confirm datasheet revision DS20006923B matches your design requirements. Ensure compatibility with SPI Modes 0 and 3. Check for any recent Product Change Notifications affecting pinout or electrical characteristics before finalizing procurement.

Selection Notes

Select this component when hardware-based serialization via a unique 128-bit ID is required without external manufacturing steps. Choose the 25CS320 over standard EEPROMs if enhanced write protection through user-definable memory partitions is necessary. Consider this part for designs operating across a wide voltage range of 1.7V to 5.5V where low standby current is critical. Verify that the required SPI clock speed aligns with your system's supply voltage constraints.

Part Context

The 25CS320 belongs to Microchip's 25CS series of Serial EEPROMs designed for high-reliability applications. It is backward compatible with 25AA320A, 25LC320A, and AT25320B devices. The series emphasizes security and data integrity through built-in ECC and unique serial numbers. It supports multiple package types including TSSOP, SOIC, MSOP, UDFN, and VDFN.

Replacement Considerations

The datasheet explicitly states backward compatibility with 25AA320A, 25LC320A, and AT25320B. These parts may serve as direct replacements if pinout and electrical specifications match the existing design constraints.