25LC640AXT-I/ST

Overview

The Microchip Technology 25LC640AXT-I/ST is a 64-Kbit (8192 x 8-bit) Serial Electrically Erasable PROM. It utilizes an SPI-compatible serial bus for data access, supporting clock frequencies up to 10 MHz at VCC levels between 4.5V and 5.5V. The device operates within a voltage range of 2.5V to 5.5V and features industrial temperature ratings from -40°C to +85°C. It includes a 32-byte page write buffer, self-timed erase/write cycles with a maximum duration of 5 ms, and high reliability specifications including 1,000,000 erase/write cycles and over 200 years of data retention.

Feature Summary

• Supports high-speed SPI communication with clock frequencies reaching 10 MHz
• Includes built-in hardware write protection via the WP pin and STATUS register bits
• Features power-on/off data protection circuitry and a write enable latch mechanism

Applications

• Microcontroller system data storage
• Configuration parameter storage
• Calibration data retention

Procurement Notes

Verify that the specific ordering suffix 'XT' corresponds to the TSSOP package variant as documented in official Microchip datasheets. Confirm the 'I' designation matches the required industrial temperature range of -40°C to +85°C. Ensure compatibility with the 2.5V to 5.5V operating voltage range for your target application environment before finalizing procurement.

Selection Notes

Select this component when a non-volatile memory solution requires SPI interface compatibility and robust write protection features. It is suitable for applications needing high endurance and long-term data retention without requiring complex parallel interfaces. Consider the 32-byte page size limitations for write operations when designing firmware algorithms.

Part Context

This part belongs to the 25LC640A family of 64-Kbit Serial EEPROMs manufactured by Microchip Technology. The family shares identical functional characteristics but differs in package types and voltage ranges. The 'LC' prefix indicates a 2.5V minimum operating voltage, distinguishing it from the 'AA' series which supports lower voltages down to 1.8V.

Replacement Considerations

The 25AA640A serves as a functional substitute within the same family, offering identical performance with a wider voltage range starting at 1.8V.