25LC040X/ST

Overview

The Microchip Technology 25LC040X/ST is a 4 Kbit (512 x 8-bit) serial Electrically Erasable PROM housed in an 8-lead TSSOP package. It operates within a voltage range of 2.5V to 5.5V and supports a maximum clock frequency of 2 MHz. The device utilizes a standard SPI-compatible interface with separate data input (SI) and output (SO) lines, controlled by Chip Select (CS), Serial Clock (SCK), Hold (HOLD), and Write-Protect (WP) pins. It features self-timed erase and write cycles with a maximum duration of 5 ms.

Feature Summary

• Supports sequential read operations with automatic address pointer incrementation across the memory array.
• Includes hardware write protection via the WP pin and software-controlled block protection for none, one-quarter, one-half, or all of the array.
• Features built-in power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.

Applications

• Data storage in microcontroller systems requiring non-volatile memory
• Configuration parameter retention in industrial control devices
• Calibration data storage for sensor interfaces

Procurement Notes

Verify that the specific ordering suffix 'X' corresponds to the alternate pinout configuration available exclusively in the ST package, as indicated in the product identification system. Confirm the temperature grade matches the required operational environment, typically Industrial (-40°C to +85°C). Ensure compatibility with the host controller's SPI mode and voltage levels before integration.

Selection Notes

Select this component when a 4 Kbit capacity is sufficient for application requirements. The 2.5V minimum supply voltage distinguishes it from the 1.8V supported 25AA040 series. The TSSOP package is suitable for surface-mount assembly. Note that this device family is not recommended for new designs; consider the updated 25LC040A series for future projects.

Part Context

This part belongs to the 25XX040 family of 4K SPI Bus Serial EEPROMs manufactured by Microchip Technology. The 'LC' designation indicates a 2.5V to 5.5V operating voltage range, while the 'X' suffix denotes an alternate pinout configuration specific to the TSSOP package type. It serves as a low-power, high-reliability non-volatile memory solution for embedded applications.

Replacement Considerations

Public confirmed substitute part numbers include 25LC040A-I/ST for the updated A-series variant. Other compatible parts within the same family include 25LC040-I/SN and 25LC040-I/P, though these lack the alternate pinout feature associated with the 'X' suffix.