25AA040AT-I/ST

Memory IC Overview

The Microchip Technology 25AA040AT-I/ST is a 4 Kbit (512 x 8) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It operates with a supply voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 10 MHz via a SPI-compatible serial bus. The device features industrial temperature ratings from -40°C to +85°C and utilizes an 8-lead TSSOP package.

Memory IC Feature Summary

• Supports sequential read operations and page write modes for up to 16 bytes per cycle.
• Includes hardware write protection via the WP pin and software block protection for none, 1/4, 1/2, or all of the array.
• Features a HOLD input to pause serial communication without resetting the sequence.

Memory IC Applications

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

Memory IC Procurement Notes

Verify that the ordering suffix 'I' corresponds to the Industrial temperature grade (-40°C to +85°C) and 'ST' indicates the 8-lead TSSOP package. Confirm the 'A' in the part number denotes the specific revision supported by the DS21827H datasheet. Ensure the application environment remains within the specified 1.8V to 5.5V supply voltage limits.

Memory IC Selection Notes

Select this component when low-voltage operation down to 1.8V is required, distinguishing it from the 25LC040A which starts at 2.5V. Choose the TSSOP package if space-constrained surface-mount assembly is necessary. Verify that the 10 MHz SPI interface speed meets the system timing requirements.

Memory IC Part Context

This device belongs to the 25XX040A family of 4 Kbit SPI EEPROMs manufactured by Microchip Technology. It shares functional similarities with the 25LC040A but differs primarily in its lower minimum operating voltage specification. The family is designed for non-volatile data retention in embedded systems requiring reliable storage.

Memory IC Replacement Considerations

The 25LC040AT-I/ST is a compatible alternative within the same family, though it requires a higher minimum supply voltage of 2.5V compared to the 1.8V minimum of the 25AA040AT-I/ST. Other 4 Kbit SPI EEPROMs may require firmware adjustments due to differences in instruction sets or timing parameters.