EEPROM Memory IC: Microchip 25LC040A-I/ST Datasheet and Application Overview

The Microchip 25LC040A-I/ST is a 4-Kbit SPI Serial EEPROM memory integrated circuit that serves as a fundamental component for non-volatile data storage in a vast array of electronic designs. Operating from 1.8V to 5.5V, this device is exceptionally suited for both low-power portable applications and robust industrial systems. Its compatibility with the ubiquitous Serial Peripheral Interface (SPI) bus allows for easy connection to a wide range of microcontrollers and processors, simplifying board layout and firmware development.

Housed in a space-saving 8-lead TSSOP package, the 25LC040A is organized as 512 x 8 bits. It features hardware write protection via the ~WP pin, which can be used to safeguard the entire memory array from unintended write operations. The device also includes a hold function (~HOLD pin) that allows the system to pause any serial communication without resetting the sequence, which is invaluable in multi-slave SPI environments. With a maximum clock frequency of 3 MHz, it provides a sufficient data transfer rate for many common applications.

A key strength of this EEPROM is its high reliability and endurance. It is specified for over 1,000,000 erase/write cycles per byte and boasts a data retention period of more than 200 years. These characteristics make it an ideal choice for storing critical but frequently updated parameters, such as calibration data, device settings, or historical logs.

Typical applications for the 25LC040A-I/ST are diverse, including:

Consumer Electronics: Storing user preferences and calibration data in smart home devices, audio equipment, and televisions.

Industrial Automation: Holding configuration parameters and small data logs in sensors, PLCs, and control modules.

Automotive Systems: Used in non-critical modules for storing serial numbers and operational data.

Medical Devices: Retaining device settings and usage history in portable medical monitors.

Networking Equipment: Storing MAC addresses and board-specific configuration data in routers and switches.

ICGOOODFIND: The Microchip 25LC040A-I/ST is a versatile and highly reliable 4-Kbit SPI EEPROM. Its wide voltage range, small form factor, and simple SPI interface make it an excellent choice for designers needing robust non-volatile memory for parameter storage across consumer, industrial, and automotive applications.

Keywords: SPI EEPROM, Non-volatile Memory, Microchip, Serial Memory, Low-power.