25LC040A-E/SN

Overview

The Microchip Technology 25LC040A-E/SN is a 4 Kbit (512 x 8) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It operates within a supply voltage range of 2.5V to 5.5V and supports a maximum clock frequency of 10 MHz via a standard SPI-compatible serial bus. The device features low-power CMOS technology with typical standby current of 1 µA at 2.5V. It includes block write protection, self-timed erase/write cycles of 5 ms max, and high reliability with 1,000,000 endurance cycles and over 200 years data retention. It is housed in an 8-lead SOIC package.

Feature Summary

• Supports sequential read operations and page write mode for up to 16 bytes.
• Includes built-in hardware write protection via the WP pin and software control through the STATUS register.
• Features power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.
• Allows communication pausing via the HOLD pin without resetting the serial sequence.

Applications

• Microcontroller system data storage
• Configuration parameter storage
• Calibration data retention

Procurement Notes

Verify the specific suffix 'E' indicates the Automotive temperature grade (-40°C to +125°C) and 'SN' denotes the 8-lead SOIC package. Confirm RoHS compliance status as per the latest datasheet revision. Ensure the ordering code matches the required voltage and speed specifications for your application design.

Selection Notes

Select this component when an SPI interface is required for non-volatile memory with automotive-grade temperature stability. Compare against the 25AA040A variant if a lower minimum operating voltage of 1.8V is necessary instead of 2.5V. Consider the 25C040 series if industrial voltage ranges differ significantly from the LC series specifications.

Part Context

This part belongs to the 25XX040A family of 4K-bit SPI EEPROMs from Microchip Technology. The family shares identical functional architectures but varies by voltage range and temperature rating. The 'LC' designation specifically targets applications requiring operation between 2.5V and 5.5V, distinguishing it from the broader voltage coverage of the 'AA' series.

Replacement Considerations

Direct substitutes include other 25LC040A variants with different packages (e.g., PDIP, MSOP) or temperature grades (Industrial I). Cross-referencing with 25AA040A requires verifying voltage compatibility, as the AA series supports down to 1.8V while the LC series starts at 2.5V.

FAQ

How does the HOLD pin function during serial communication?

The HOLD pin suspends transmission to the device when pulled low while SCK is low. Transitions on SI, SCK, and SO are ignored, allowing the host to service higher priority interrupts. Communication resumes when HOLD is brought high while SCK is low.

What is the maximum page size for write operations?

The device supports a page write mode that allows writing up to 16 bytes of data at once. All bytes must reside within the same physical page boundary; crossing a boundary causes the address counter to roll over and overwrite existing data.