25AA640A-I/P

Memory IC Overview

The Microchip Technology 25AA640A-I/P is a 64-Kbit serial Electrically Erasable PROM featuring an SPI-compatible interface. It operates within a voltage range of 1.8V to 5.5V and supports clock frequencies up to 10 MHz at 5.5V. The device utilizes an 8192 x 8-bit organization with a 32-byte page size. It is housed in an 8-lead PDIP package and functions reliably across an industrial temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Supports Serial Peripheral Interface (SPI) communication with separate data input and output lines.
• Includes hardware write protection via the WP pin and software block protection for array segments.
• Features self-timed erase and write cycles with automatic internal timing control.

Memory IC Applications

• Data storage for configuration parameters in microcontroller systems
• Logging sensor data or event records in industrial monitoring devices
• Storing calibration constants and user settings in embedded appliances

Memory IC Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the base part number covers multiple form factors. Confirm the temperature grade corresponds to the intended operating environment. Ensure the voltage supply aligns with the 1.8V to 5.5V operational range specified in the datasheet before finalizing procurement.

Memory IC Selection Notes

Select this component when a low-pin-count nonvolatile memory solution is required for SPI-based designs. The 64-Kbit capacity suits applications needing moderate storage for system parameters. Consider the 8-lead PDIP package if through-hole mounting is necessary for mechanical stability or prototyping environments.

Memory IC Part Context

This device belongs to the 25AA640A/25LC640A family of 64K-bit serial EEPROMs. The 'I' designation indicates an industrial temperature rating, while '/P' specifies the 8-lead Plastic Dual In-line Package. It shares architectural similarities with other members of the series but differs in voltage ranges and packaging options.

Memory IC Replacement Considerations

The 25LC640A-I/P serves as a direct functional substitute within the same family, though it requires a minimum supply voltage of 2.5V compared to the 1.8V lower limit of the 25AA640A. Verify voltage compatibility before substitution.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the host to pause transmission mid-sequence without resetting the address pointer. Pulling HOLD low suspends data transfer on SI/SCK, and pulling it high resumes operation from the exact point of suspension.

What is the maximum page write size for this device?

The device supports a page size of 32 bytes. A single page write operation can transmit up to 32 bytes of data, provided all bytes reside within the same physical page boundary.