25AA040AT-I/SN

Memory IC Overview

The Microchip Technology 25AA040AT-I/SN is a 4 Kbit (512 x 8) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It operates via a SPI-compatible serial bus with a maximum clock frequency of 10 MHz. The device supports a supply voltage range of 1.8 V to 5.5 V and functions within an industrial temperature range of -40°C to +85°C. It features self-timed erase and write cycles, block write protection, and data retention exceeding 200 years.

Memory IC Feature Summary

• Supports sequential read operations and page write mode for up to 16 bytes per cycle.
• Includes built-in power-on/off data protection circuitry and a dedicated write-protect pin.
• Features a hold input that pauses communication without resetting the serial sequence.

Memory IC Applications

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

Memory IC Procurement Notes

Verify the specific suffix 'I' confirms the Industrial temperature grade (-40°C to +85°C) and 'SN' denotes the SOIC-8 package. Confirm the 'T' indicates tape-and-reel packaging. Ensure the datasheet DS21827H matches the required electrical characteristics for your operating voltage.

Memory IC Selection Notes

Select this component when low-voltage operation down to 1.8 V is required alongside standard SPI compatibility. It is suitable for applications needing high endurance and long-term data retention. Compare against the 25LC040A if a higher minimum voltage of 2.5 V is acceptable for cost or availability reasons.

Memory IC Part Context

This part belongs to the 25XX040A family of 4 Kbit SPI EEPROMs from Microchip Technology. The family includes variants like the 25LC040A which differ primarily in their minimum operating voltage requirements. These devices are designed for non-volatile data storage in embedded systems requiring reliable byte-level access.

Memory IC Replacement Considerations

The 25LC040AT-I/SN is a direct functional substitute within the same package, though it requires a minimum supply voltage of 2.5 V instead of 1.8 V. Verify voltage headroom in the target design before substitution.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the user to pause transmission to the device mid-sequence without resetting the serial pointer. Transitions on SI, SCK, and SO are ignored while held low, and communication resumes when the pin is brought high.

What is the mechanism for preventing inadvertent writes?

Writes are inhibited by default upon power-up. A WREN instruction must be issued to set the write enable latch. Additionally, the WP pin can force all writes to be disabled regardless of the latch state.