25AA256T-E/ST

Memory IC Overview

The Microchip Technology 25AA256T-E/ST is a 256 Kbit Serial Electrically Erasable PROM featuring a 32,768 x 8-bit organization. It utilizes an SPI-compatible serial bus with SCK, SI, SO, and CS signals for communication. The device supports a maximum clock frequency of 10 MHz at VCC voltages between 4.5V and 5.5V. It operates within a supply voltage range of 1.8V to 5.5V and includes a 64-byte page write buffer. The component is housed in an 8-lead TSSOP package and is rated for an industrial temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Supports block write protection allowing selection of none, one-quarter, one-half, or all array segments via status register configuration.
• Includes built-in power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.
• Features a HOLD input pin that suspends serial communication without resetting the sequence, enabling host interrupt servicing.

Memory IC Applications

• Data logging applications requiring non-volatile storage
• Configuration parameter storage in embedded systems
• Calibration data retention in industrial controllers

Memory IC Procurement Notes

Verify the specific suffix 'E' confirms the extended temperature rating if operation above 85°C is required, though this part number specifies Industrial range. Confirm the 'T' suffix indicates tape and reel packaging for automated assembly. Ensure the source documentation matches the exact part number to validate the 1.8V minimum operating voltage characteristic distinct from other variants.

Memory IC Selection Notes

Select this component when an SPI interface is preferred over I2C for system architecture compatibility. The 25AA256 variant specifically supports lower voltage operation down to 1.8V compared to the 25LC256 series. Consider the 64-byte page size limitation for write operations, which requires software management to avoid data wrapping across page boundaries.

Memory IC Part Context

This device belongs to the 25XX256 family of Serial EEPROMs manufactured by Microchip Technology. It shares functional similarities with the 25LC256 but differs in its supported voltage range. The family offers high reliability with specified endurance and data retention characteristics suitable for long-term data storage requirements in electronic devices.

Memory IC Replacement Considerations

The 25AA256T-I/ST serves as a direct replacement within the same package and feature set, differing only in the guaranteed temperature range specification.