25AA640A-E/ST

Memory IC Overview

The Microchip Technology 25AA640A-E/ST is a 64-Kbit (8192 x 8-bit) serial Electrically Erasable PROM accessed via an SPI-compatible bus. It operates within a supply voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 10 MHz at higher voltages. The device features a 32-byte page size, self-timed erase/write cycles with a maximum duration of 5 ms, and high reliability including 1 million erase/write cycles and over 200 years of data retention. It is qualified under the AEC-Q100 standard for automotive applications and functions across an extended temperature range from -40°C to +125°C.

Memory IC Feature Summary

• Supports Serial Peripheral Interface (SPI) communication with separate data in and out lines.
• Includes hardware write protection via the WP pin and software block protection for array segments.
• Features a HOLD input to pause serial sequences without resetting the communication state.
• Provides built-in power-on/off data protection circuitry and a write enable latch.

Memory IC Applications

• Automotive electronic systems requiring AEC-Q100 qualification
• Microcontroller-based data logging and configuration storage
• Industrial control systems operating in extended temperature environments

Memory IC Procurement Notes

Verify that the specific ordering suffix matches the required package type and temperature grade. Confirm the 'E' designation corresponds to the extended temperature range (-40°C to +125°C). Ensure compatibility with the host system's SPI voltage levels and interface timing requirements before finalizing procurement.

Memory IC Selection Notes

Select this component when an SPI EEPROM with automotive qualification is required. The 25AA640A variant supports lower voltage operation down to 1.8V compared to the 25LC640A. Choose the ST suffix specifically for the TSSOP-8 package format. Consider the 32-byte page write limitation when designing firmware to prevent data corruption across page boundaries.

Memory IC Part Context

This part belongs to the 25XX640A family of 64-Kbit serial EEPROMs manufactured by Microchip Technology. The family includes variants such as the 25LC640A, which differs primarily in its minimum operating voltage. The 25AA640A series is designed for applications needing non-volatile memory with robust write protection and high endurance characteristics.

Memory IC Replacement Considerations

The 25LC640A serves as a functional alternative within the same family, though it requires a minimum supply voltage of 2.5V instead of 1.8V. Verify that the replacement part meets the specific voltage and temperature constraints of the target application.