25AA040A-I/ST

Memory IC Overview

The Microchip Technology 25AA040A-I/ST is a 4 Kbit (512 x 8-bit) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It operates within a supply voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 10 MHz. The device utilizes an SPI-compatible serial bus for communication, featuring a write page mode capable of handling up to 16 bytes per cycle. It includes block write protection capabilities and self-timed erase/write cycles with a maximum duration of 5 ms.

Memory IC Feature Summary

• Supports sequential read operations and write page mode for efficient data transfer across the SPI interface.
• Provides hardware-based write protection via the WP pin and software-configurable block protection levels.
• Includes built-in power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.

Memory IC Applications

• Microcontroller systems requiring non-volatile storage for configuration parameters
• Data logging applications needing reliable byte-level or page-level memory access
• Embedded devices utilizing standard SPI bus architectures for peripheral communication

Memory IC Procurement Notes

Verify that the ordering suffix 'ST' corresponds to the TSSOP package type as specified in the datasheet. Confirm the 'I' designation indicates Industrial temperature range operation (-40°C to +85°C). Ensure the component matches the 25AA040A variant which supports the 1.8V minimum voltage requirement, distinct from the 2.5V minimum of the 25LC040A series.

Memory IC Selection Notes

Select this component when a low-voltage start capability down to 1.8V is required alongside standard 5.5V operation. The TSSOP package offers a compact surface-mount solution suitable for space-constrained designs. Consider the 10 MHz clock speed for high-throughput SPI applications and verify that the 16-byte page size aligns with the application's write granularity requirements.

Memory IC Part Context

This part belongs to the 25XX040A family of 4 Kbit SPI EEPROMs manufactured by Microchip Technology. The 'AA' prefix denotes support for a 1.8V to 5.5V voltage range, differentiating it from the 'LC' variant which requires a minimum of 2.5V. The 'I' suffix specifies industrial temperature grading, while 'ST' identifies the specific 8-lead Thin Shrink Small Outline Package.

Memory IC Replacement Considerations

The 25LC040A-I/ST serves as a direct functional substitute within the same package, provided the system voltage does not drop below 2.5V. Other compatible parts include variants with different package suffixes such as SN (SOIC) or MS (MSOP), assuming mechanical fitment allows.