25LC640A-E/ST

Overview

The Microchip Technology 25LC640A-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 a maximum clock frequency of 10 MHz at higher voltages. The device utilizes an 8192 x 8-bit organization with a 32-byte page size. It is qualified under AEC-Q100 standards for automotive applications and functions reliably across an extended temperature range from -40°C to +125°C.

Feature Summary

• Supports serial communication via standard SPI bus signals including SCK, SI, SO, and CS.
• Includes built-in hardware write protection mechanisms such as power-on/off data protection and a dedicated write-protect pin.
• Features a hold function that allows suspension of serial transmission without resetting the sequence.

Applications

• Automotive embedded systems requiring AEC-Q100 qualification
• Industrial control configurations needing non-volatile storage
• Consumer electronics utilizing low-power CMOS technology

Procurement Notes

Verify the specific suffix 'E' confirms the extended temperature rating (-40°C to +125°C) and 'ST' indicates the TSSOP package. Confirm the 'LC' designation ensures the minimum operating voltage is 2.5V rather than 1.8V. Cross-reference the datasheet revision DS20001830G for accurate electrical characteristics and timing parameters before finalizing procurement specifications.

Selection Notes

Select this component when an SPI EEPROM requires operation above 2.5V minimum voltage but needs lower power consumption than parallel alternatives. The extended temperature grade suits harsh environments where industrial ratings are insufficient. Ensure the host microcontroller supports the required SPI modes and can manage the write enable latch sequences defined in the instruction set.

Part Context

This part belongs to the 25LC640A family of 64-Kbit serial EEPROMs manufactured by Microchip Technology. It shares architectural similarities with the 25AA640A, differing primarily in the minimum supply voltage requirements. The device is designed for high-reliability applications offering significant endurance and long-term data retention capabilities.

Replacement Considerations

The 25AA640A-E/ST serves as a functional substitute if the system supports a lower minimum voltage of 1.8V. Verify that the replacement maintains compatibility with the existing SPI interface timing and voltage levels to ensure seamless integration without hardware modifications.