25LC640XT-I/ST

Overview

The Microchip Technology 25LC640XT-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 2 MHz at VCC voltages between 2.5V and 5.5V. It features low-power CMOS technology with typical standby current of 500 nA and read current of 500 μA. The component includes built-in write protection mechanisms and operates within the industrial temperature range of -40°C to +85°C.

Feature Summary

• Supports SPI-compatible serial interface with separate data in and out lines
• Includes block write protection allowing selective array segment locking
• Features power-on/off data protection circuitry and write enable latch
• Provides hold functionality to pause serial transmission without resetting sequence

Applications

• Microcontroller system data storage
• Configuration parameter retention
• Calibration value logging

Procurement Notes

Verify the specific suffix 'XT' against official Microchip documentation to confirm package type and tape-and-reel specifications. Ensure the Industrial temperature grade (-40°C to +85°C) matches application requirements. Confirm voltage compatibility with the 2.5V to 5.5V operating range before integration.

Selection Notes

Select this component for applications requiring non-volatile memory accessible via standard SPI interfaces. It is suitable for systems needing moderate storage density with hardware-level write protection capabilities. Consider the 32-byte page size when designing write algorithms to optimize performance.

Part Context

This part belongs to the 25LC640 series of 64 Kbit Serial EEPROMs from Microchip Technology. It is designed as a drop-in replacement for similar capacity devices but offers specific voltage and speed characteristics defined by the LC variant. The datasheet notes that this generation is not recommended for new designs, suggesting newer alternatives like the 25LC640A.

Replacement Considerations

Public confirmed substitute: 25LC640A-I/ST.