25AA640A-E/SN

Memory IC Overview

The Microchip Technology 25AA640A-E/SN is a 64-Kbit serial Electrically Erasable PROM featuring an SPI-compatible interface. It operates within a voltage range of 1.8V to 5.5V and supports clock frequencies up to 10 MHz at higher voltages. The device utilizes an 8192 x 8-bit organization with a 32-byte page size. It is housed in an 8-lead SOIC package and certified for the extended industrial temperature range of -40°C to +125°C.

Memory IC Feature Summary

• Supports sequential read operations with automatic address pointer incrementation and rollover capabilities.
• Includes built-in write protection mechanisms such as power-on/off data protection, a write enable latch, and a dedicated write-protect pin.
• Features block write protection allowing configuration to protect none, one-quarter, one-half, or all of the memory array.

Memory IC Applications

• Microcontroller systems requiring non-volatile data storage via SPI ports
• Industrial control applications operating in extended temperature environments
• Automotive electronic modules requiring AEC-Q100 qualified components

Memory IC Procurement Notes

Verify that the ordering suffix correctly specifies the SN package type and E temperature grade. Confirm compliance with RoHS standards and ensure the specific revision matches project requirements. Cross-reference datasheet DS20001830G for accurate electrical characteristics before finalizing procurement orders.

Memory IC Selection Notes

Select this component when an SPI EEPROM is required for extended temperature operation up to 125°C. Ensure the system voltage falls within the 1.8V to 5.5V range. Consider the 32-byte page write limit and block protection features when designing the memory management software architecture.

Memory IC Part Context

This part belongs to the 25AA640A/25LC640A family of 64K-bit serial EEPROMs. The 'E' suffix denotes the extended temperature range variant (-40°C to +125°C), while 'SN' indicates the 8-lead Small Outline Integrated Circuit (SOIC) package. It shares functional similarities with other members of the 25XX640A series but differs in voltage thresholds and thermal specifications.

Memory IC Replacement Considerations

The 25LC640A serves as a direct functional substitute within the same family, though it requires a minimum supply voltage of 2.5V compared to the 1.8V minimum of the 25AA640A. Verify voltage compatibility before substitution.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows suspension of transmission mid-sequence without resetting the serial sequence. It must be held low while SCK is low to pause communication, tri-stating the SO pin until released.

What determines the write protection status of the memory array?

Write protection is determined by the Block Protection (BP0 and BP1) bits in the STATUS register, which can be configured to protect none, 1/4, 1/2, or all of the array.