25LC020A-E/ST

Overview

The Microchip Technology 25LC020A-E/ST is a 2 Kbit (256 x 8-bit) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It features a maximum clock frequency of 10 MHz and operates within a supply voltage range of 2.5 V to 5.5 V. The device supports up to 1,000,000 erase/write cycles with data retention exceeding 200 years. It utilizes an SPI-compatible serial bus for communication and includes block write protection capabilities.

Feature Summary

• Supports sequential read operations and page write modes accommodating up to 16 bytes per cycle.
• Includes built-in hardware write protection via the WP pin and software-controlled block protection for array segments.
• Features self-timed erase and write cycles that automatically reset the write enable latch upon completion.

Applications

• Storing unique device identification numbers and production batch codes
• Persisting calibration parameters and user configuration settings
• Recording operational logs or fault history in embedded systems

Procurement Notes

Verify the specific suffix 'E' confirms the extended industrial temperature rating (-40°C to +125°C) and the 'ST' suffix indicates the SOT-23 package type. Confirm RoHS compliance status as required by your manufacturing standards. Ensure the design accommodates the 8-pin SOT-23 footprint dimensions and thermal characteristics specified in the datasheet packaging section.

Selection Notes

Select this component when an SPI interface is preferred over I2C for simpler protocol implementation and higher speed requirements up to 10 MHz. The extended temperature grade is suitable for harsh environments where standard industrial ratings are insufficient. Consider the low standby current if power conservation during idle states is a critical system constraint.

Part Context

This part belongs to the 25XX020A family of 2 Kbit SPI EEPROMs from Microchip Technology. It shares identical memory architecture and instruction sets with the 25AA020A variant, differing primarily in the minimum operating voltage threshold. The family provides non-volatile storage solutions for microcontroller-based applications requiring reliable data retention.

Replacement Considerations

The 25LC020A-I/ST serves as a direct functional substitute with an adjusted industrial temperature range (-40°C to +85°C). Verify that the application environment remains within the lower temperature limits of the '-I' grade before swapping components.

FAQ

How does the HOLD pin function during SPI communication?

The HOLD pin allows the host to pause serial communication without resetting the sequence. When pulled low while SCK is low, inputs are ignored and SO goes high-impedance. Communication resumes when HOLD is brought high while SCK is low.

What happens if a page write crosses a physical page boundary?

If a page write operation attempts to cross a physical page boundary, the data wraps around to the beginning of the current page instead of writing to the next page. Application software must prevent writes that exceed the page limit.