25LC640AX-I/ST

Overview

The Microchip Technology 25LC640AX-I/ST is a 64-Kbit (8192 x 8-bit) Serial Electrically Erasable PROM. It utilizes an SPI-compatible serial bus for communication, requiring SCK, SI, SO, and CS signals. The device supports a maximum clock frequency of 10 MHz at VCC levels between 4.5V and 5.5V. Operating voltage ranges from 2.5V to 5.5V. It features self-timed erase and write cycles with a maximum duration of 5 ms. The component includes block write protection capabilities and built-in power-on/off data protection.

Feature Summary

• Supports sequential read operations with automatic address pointer incrementation
• Includes hardware write-protect pin and software-configurable block protection
• Features low-power CMOS technology with standby current as low as 1 µA
• Provides high reliability with over one million erase/write cycle endurance

Applications

• Microcontroller system configuration storage
• Calibration parameter persistence
• Log data buffering
• Device identification and security code storage

Procurement Notes

Verify the specific suffix 'X' against official Microchip documentation to confirm pinout orientation and package details. Ensure the industrial temperature range (-40°C to +85°C) matches application requirements. Confirm RoHS compliance status through the manufacturer's latest datasheet revision notes.

Selection Notes

Select this component when SPI interface compatibility is required with a 64-Kbit capacity. Consider the 32-byte page size limitation for write operations. Evaluate the 2.5V minimum supply voltage against system power rails. Verify that the 10 MHz clock speed meets the host controller's timing constraints.

Part Context

This part belongs to the 25LC640A series of serial EEPROMs manufactured by Microchip Technology. It shares functional similarities with the 25AA640A but differs in operating voltage specifications. The series is designed for non-volatile data storage in embedded systems requiring reliable byte-level access via standard SPI protocols.

Replacement Considerations

25LC640A-I/ST