25LC640AXT-E/ST

Overview

The Microchip Technology 25LC640AXT-E/ST is a 64-Kbit Serial Electrically Erasable PROM featuring an SPI-compatible interface. It operates within a voltage range of 2.5V to 5.5V and supports clock frequencies up to 10 MHz at 5.5V. The device utilizes an 8192 x 8-bit organization with a 32-byte page size. It offers high reliability, including 1,000,000 erase/write cycles and data retention exceeding 200 years. The component is housed in an 8-lead TSSOP package and is qualified for the Automotive AEC-Q100 standard, supporting an extended temperature range from -40°C to +125°C.

Feature Summary

• Supports serial communication via a four-wire SPI bus with separate data input and output lines.
• Includes built-in write protection mechanisms such as power-on/off data protection and a dedicated write-protect pin.
• Features block write protection allowing selective protection of none, one-quarter, one-half, or all memory array segments.
• Provides a hold function to pause serial transmission without resetting the sequence.

Applications

• Automotive electronic systems requiring AEC-Q100 qualification
• Industrial control applications needing non-volatile data storage
• Microcontroller-based systems utilizing SPI interfaces
• Embedded devices requiring secure configuration parameter storage

Procurement Notes

Verify the specific ordering suffix 'XT' against official Microchip documentation to confirm tape-and-reel packaging specifications and any unique marking requirements. Ensure the Extended temperature grade (E) matches the operational environment constraints. Confirm RoHS compliance status through current datasheets before finalizing procurement orders.

Selection Notes

Select this component when an SPI EEPROM with automotive qualification is required. The 25LC640A variant specifically requires a minimum supply voltage of 2.5V, unlike the 25AA640A which supports lower voltages. Consider the 8-lead TSSOP package dimensions for PCB layout compatibility. Verify that the 32-byte page write limit aligns with the application's data throughput requirements.

Part Context

This part belongs to the 25XX640A family of 64-Kbit Serial EEPROMs manufactured by Microchip Technology. The family includes variants with different voltage ranges and temperature grades. The 25LC640A series is distinguished by its 2.5V minimum operating voltage compared to the 1.8V support in the 25AA640A series. All members share identical functional architectures and instruction sets.

Replacement Considerations

The 25LC640AT-E/ST serves as a direct replacement for the 25LC640AXT-E/ST, differing only in the absence of the X designation which typically denotes specific reel packaging variations. Both parts share identical electrical characteristics, pinouts, and functionality. Verify package markings if traceability is critical.