25LC640AT-E/MS

Overview

The Microchip Technology 25LC640AT-E/MS is a 64-Kbit (8192 x 8-bit) Serial Electrically Erasable PROM. It utilizes an SPI-compatible serial bus with SCK, SI, SO, and CS signals for data access. 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 a 32-byte page size and self-timed erase/write cycles with a maximum duration of 5 ms. The component operates within an extended temperature range of -40°C to +125°C and is housed in an 8-lead MSOP package.

Feature Summary

• Supports high-speed SPI communication with a maximum clock frequency of 10 MHz
• Includes hardware write protection via the WP pin and software block protection through the STATUS register
• Features a HOLD input to suspend serial transmission without resetting the sequence
• Provides built-in power-on/off data protection and a write enable latch

Applications

• Microcontroller system data storage
• Configuration parameter retention
• Calibration value storage
• Device identification information logging

Procurement Notes

Verify that the ordering suffix 'E' corresponds to the Extended temperature range (-40°C to +125°C) rather than Industrial grade. Confirm the 'T' suffix indicates tape-and-reel packaging suitable for automated assembly. Ensure the 'MS' designation matches the required 8-lead MSOP footprint. Cross-reference the specific revision level against the latest datasheet DS20001830G to confirm compatibility with current manufacturing standards.

Selection Notes

Select this part when an SPI interface is preferred over I2C for memory applications requiring higher throughput. The 25LC640A series is designed for low-power CMOS operation, making it suitable for battery-powered systems. The availability of both industrial and extended temperature grades allows for flexibility in environmental deployment. The 32-byte page buffer simplifies write operations by reducing the number of internal write cycles required for larger data blocks.

Part Context

This component belongs to the 25XX640A family of 64-Kbit Serial EEPROMs manufactured by Microchip Technology. The family includes variants such as the 25AA640A and 25LC640A, which share identical functional specifications but differ in supply voltage ranges and operating temperature classifications. The 25LC640A specifically targets applications requiring a minimum supply voltage of 2.5V.

Replacement Considerations

The 25LC640A-I/MS serves as a direct replacement for units requiring the Industrial temperature range (-40°C to +85°C). Verify that substitute components maintain the same 8-lead MSOP package dimensions and pinout configuration to ensure mechanical compatibility.