25LC040/P

Overview

The Microchip Technology 25LC040/P is a 4 Kbit (512 x 8-bit) serial Electrically Erasable PROM housed in an 8-lead Plastic Dual In-line package. It operates within a supply voltage range of 2.5 V to 5.5 V and supports a maximum clock frequency of 2 MHz. The device utilizes a Serial Peripheral Interface (SPI) compatible bus for data access, featuring low-power CMOS technology with typical standby current of 500 nA. It offers high reliability with 1 million write endurance cycles and over 200 years of data retention.

Feature Summary

• Supports SPI-compatible serial communication with separate data input and output lines controlled by Chip Select and Serial Clock inputs.
• Includes built-in hardware write protection via the Write-Protect pin and software-based block protection for array segments.
• Features self-timed erase and write cycles with automatic address pointer incrementation for sequential read operations.

Applications

• Storage of critical configuration parameters and calibration data in industrial control systems
• Retention of device identification codes and unique serial numbers in embedded devices
• Logging operational status flags and event counters in microcontroller-based applications

Procurement Notes

Verify that the component matches the specific 25LC040 variant requiring a 2.5 V minimum operating voltage, distinct from the 1.8 V or 4.5 V variants. Confirm the PDIP package designation aligns with through-hole mounting requirements. Ensure the Industrial temperature grade meets the application's thermal specifications before finalizing procurement.

Selection Notes

Select this component when a 4 Kbit non-volatile memory solution is required with a 2.5 V to 5.5 V operating range. It is suitable for designs needing robust write protection mechanisms and standard SPI interface compatibility. Consider the PDIP package form factor if through-hole assembly is mandated by the PCB layout constraints.

Part Context

This part belongs to the 25XX040 family of 4 Kbit serial EEPROMs manufactured by Microchip Technology. It shares functional similarities with the 25AA040 and 25C040 models but differs in its specific voltage operating window and maximum clock speed capabilities defined by the datasheet specifications.

Replacement Considerations

Public confirmed substitute part numbers: 25LC040/SN, 25LC040/ST, 25LC040/P-I

FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the user to pause serial communication without resetting the sequence. When pulled low while SCK is low, it places the device in a high-impedance state until brought high again.

What is the purpose of the Write Enable Latch?

The Write Enable Latch must be set via the WREN instruction before any write operation can be completed. It resets automatically after power-up, successful write execution, or upon assertion of the WP pin.