24LCS21A/SN

Memory IC Overview

The Microchip Technology 24LCS21A/SN is a 128 x 8-bit dual-mode Electrically Erasable PROM housed in an 8-pin SOIC package. It operates on a single supply voltage ranging from 2.5V to 5.5V and supports I²C-compatible 2-wire serial interfaces. The device features two operational modes: Transmit-Only mode, which outputs memory data via the VCLK pin, and Bidirectional mode for standard read/write operations via SCL and SDA. It includes hardware write protection, a page-write buffer for up to eight bytes, and ensures 1,000,000 erase/write cycles with data retention exceeding 200 years.

Memory IC Feature Summary

• Implements DDC1/DDC2 interface standards for monitor identification and configuration storage
• Features dual-mode operation allowing transition between unidirectional transmission and bidirectional I²C communication
• Includes hardware write-protect capabilities controlled by dedicated pins and internal fuses
• Utilizes low-power CMOS technology with standby current as low as 10 μA at 5.5V

Memory IC Applications

• Monitor identification and configuration storage
• Display Data Channel (DDC) applications
• Storage of control information requiring serial transmission

Memory IC Procurement Notes

Verify that the specific suffix 'SN' corresponds to the Plastic SOIC package variant rather than PDIP. Confirm the temperature range designation matches industrial requirements (-40°C to +85°C). Ensure the ordering code aligns with the exact capacity and interface specifications required for the target application design.

Memory IC Selection Notes

Select this component when DDC compliance or dual-mode functionality is required. The 24LCS21A is suitable for applications needing both continuous data output and standard I²C access. Consider the 8-byte page write buffer for efficiency. Verify power supply constraints against the 2.5V minimum operating voltage requirement.

Memory IC Part Context

The 24LCS21A belongs to the 24LCS21 series of dual-mode I²C Serial EEPROMs manufactured by Microchip Technology. This series is specifically engineered for display and monitor applications where configuration data must be accessible via standard DDC protocols while maintaining compatibility with general-purpose I²C controllers.

Memory IC Replacement Considerations

The datasheet notes that the predecessor 24LCS21 is not recommended for new designs and advises using the 24LCS21A instead. No other direct substitute part numbers are explicitly confirmed in the provided documentation.