25LC640AX-E/ST

Overview

The Microchip Technology 25LC640AX-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 maximum clock frequencies up to 10 MHz at higher voltages. The device utilizes an 8192 x 8-bit organization with 32-byte page write capabilities. It includes built-in write protection, block write protection, and power-on/off data protection circuitry. The component is qualified under AEC-Q100 standards for automotive applications and supports extended temperature ranges.

Feature Summary

• Supports serial communication via standard SPI bus signals including SCK, SI, SO, and CS.
• Includes hardware write-protect pin (WP) and software-controlled block protection for array segments.
• Features internal self-timed erase and write cycles with automatic status polling capability.
• Provides hold functionality to pause serial transmission without resetting the sequence.

Applications

• Automotive embedded systems requiring AEC-Q100 qualified non-volatile memory
• Industrial control devices needing reliable configuration storage
• Consumer electronics utilizing low-power serial EEPROM for parameter retention

Procurement Notes

Verify that the ordering suffix 'X' corresponds to the specific rotated pinout package variant documented in official Microchip datasheets. Confirm the 'E' suffix indicates the extended temperature range rating required for your application environment. Ensure compatibility with the 8-lead TSSOP physical dimensions during PCB layout.

Selection Notes

Select this part when an SPI interface is preferred over I2C for simpler protocol implementation. Choose the Extended temperature grade if operating conditions exceed standard industrial limits. Consider the 32-byte page size for write efficiency compared to byte-only programming alternatives.

Part Context

This component belongs to the 25LC640A family of 64-Kbit SPI Serial EEPROMs manufactured by Microchip Technology. It shares architectural similarities with the 25AA640A but differs in minimum supply voltage requirements. The family is designed for general-purpose non-volatile data storage in microcontroller-based systems.

Replacement Considerations

25LC640AT-E/ST