25C040-E/SN

Memory IC Overview

The Microchip Technology 25C040-E/SN is a 4 Kbit (512 x 8) serial Electrically Erasable PROM accessed via an SPI-compatible bus. It operates within a VCC range of 4.5V to 5.5V with a maximum clock frequency of 3 MHz. The device supports industrial (-40°C to +85°C) and automotive (-40°C to +125°C) temperature ranges, featuring self-timed write cycles of 5 ms max, 1M cycle endurance, and >200 years data retention. It is housed in an 8-lead SOIC package.

Memory IC Feature Summary

• Supports sequential read operations and 16-byte page writes with self-timed erase and write cycles.
• Includes built-in write protection mechanisms such as power-on/off data protection, a write enable latch, and a hardware write-protect pin.
• Features block write protection allowing selection of none, 1/4, 1/2, or all array segments for security.

Memory IC Applications

• Microcontroller systems requiring non-volatile storage for configuration parameters.
• Automotive electronic control units operating under extended temperature conditions.
• Industrial devices needing reliable data logging with high endurance specifications.

Memory IC Procurement Notes

Verify the specific suffix 'E' confirms the automotive temperature grade (-40°C to +125°C) and 'SN' indicates the SOIC package. Confirm RoHS compliance status through official datasheets. Check for current manufacturer recommendations regarding new design usage, as legacy parts may have replacement suggestions.

Memory IC Selection Notes

Select this component when a 5V supply range (4.5V–5.5V) and 3 MHz SPI speed are required. Ensure the application demands the wider automotive temperature range compared to standard industrial grades. Verify that the 8-pin SOIC footprint matches the PCB layout constraints.

Memory IC Part Context

This part belongs to the 25XX040 family of 4Kbit SPI Serial EEPROMs from Microchip Technology. It shares architectural similarities with the 25AA040 and 25LC040 but differs in voltage tolerance and temperature rating. The 'E' suffix specifically denotes the automotive-grade reliability and extended thermal performance.

Memory IC Replacement Considerations

Consult the datasheet for recommended alternatives if the part is marked not recommended for new designs. Potential substitutes include updated variants within the same memory architecture family that maintain compatible pinouts and electrical characteristics.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin suspends transmission without resetting the sequence. It must be held low while SCK is low to pause, and brought high while SCK is low to resume.

What happens to the write enable latch upon power-up?

The write enable latch is reset on power-up, preventing inadvertent writes until a WREN instruction is successfully executed.