25AA128-I/ST

Memory IC Overview

The Microchip Technology 25AA128-I/ST is a 128 Kbit (16,384 x 8-bit) Serial Electrically Erasable PROM accessed via an SPI-compatible serial bus. It operates within a supply voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 10 MHz at 5.5V. The device features a 64-byte page write buffer, self-timed erase/write cycles with a maximum duration of 5 ms, and high reliability including 1,000,000 erase/write cycles and data retention exceeding 200 years. It is housed in an 8-lead TSSOP package and functions within an industrial temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Supports sequential read operations and page writes up to 64 bytes within a single physical page boundary.
• Includes built-in hardware write protection via the WP pin and software block protection for none, 1/4, 1/2, or all of the array.
• Features power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.
• Allows communication suspension via the HOLD pin without resetting the serial sequence.

Memory IC Applications

• Data storage in microcontroller systems requiring non-volatile memory
• Configuration parameter storage in industrial control devices
• Calibration data retention in sensor interfaces

Memory IC Procurement Notes

Verify the specific ordering suffix matches the required package type and temperature grade. Confirm that the 'I' designation corresponds to the industrial temperature range (-40°C to +85°C). Ensure the voltage supply requirements align with the 1.8V minimum specification for the 25AA128 variant. Check for RoHS compliance status if required by assembly standards.

Memory IC Selection Notes

Select this component when an SPI interface is preferred over I2C for higher speed data access. Choose the 25AA128 over the 25LC128 if operation below 2.5V down to 1.8V is necessary. Consider the 64-byte page size for write efficiency and verify that the 8-lead TSSOP footprint fits the PCB layout constraints.

Memory IC Part Context

This part belongs to the 25XX128 family of 128 Kbit SPI Serial EEPROMs from Microchip Technology. It shares functional similarities with the 25LC128 but differs in its lower minimum operating voltage. The family is designed for applications requiring reliable, low-power non-volatile storage with standard SPI compatibility.

Memory IC Replacement Considerations

The 25LC128-I/ST is a functionally similar alternative within the same datasheet, though it requires a minimum supply voltage of 2.5V instead of 1.8V. Verify voltage headroom before substitution.