24LC21A-I/SN

Memory IC Overview

The Microchip Technology 24LC21A-I/SN is a 1Kb (128 x 8) dual-mode serial EEPROM 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 interfaces with clock frequencies up to 400 kHz at 5V or 100 kHz at 2.5V. The device features a page write buffer for eight bytes, self-timed write cycles of 10 ms, and access times of 3500 ns in standard mode. Designed for industrial applications, it functions within a temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Dual-mode operation supporting both Transmit-Only (DDC1) and Bidirectional (I2C/DDC2) protocols
• Hardware write protection capability via the VCLK pin logic level
• High endurance rated for one million erase/write cycles with over 200 years data retention
• Integrated noise protection using Schmitt Trigger inputs and spike suppression filters

Memory IC Applications

• Monitor identification and EDID storage compliant with DDC standards
• Configuration and control information storage in embedded systems
• Industrial equipment requiring non-volatile memory with hardware write protection

Memory IC Procurement Notes

Verify that the specific ordering suffix matches the required package type and temperature grade. Confirm that the component meets RoHS compliance requirements for your manufacturing process. Ensure the supplier provides valid traceability documentation consistent with Microchip's quality standards. Cross-reference the manufacturer part number against official datasheets to confirm functional specifications before integration.

Memory IC Selection Notes

Select this component when a dual-mode interface is necessary for monitor identification or general serial storage. It is suitable for designs requiring hardware-level write protection without additional logic gates. Consider the 8-byte page buffer size for efficient data writing operations. Verify that the system power supply remains stable above 1.5V to ensure proper internal logic operation during read/write cycles.

Memory IC Part Context

This device belongs to the 24LC21 series of serial EEPROMs manufactured by Microchip Technology. It serves as a direct pin-and-function compatible replacement for the legacy 24LC21 model while offering enhanced dual-mode capabilities. The 'I' designation indicates the industrial temperature rating, and 'SN' specifies the surface-mount SOIC package format.

Memory IC Replacement Considerations

The 24LC21A is functionally compatible with the original 24LC21. Designers should verify that existing firmware handles the dual-mode transition correctly if migrating from older single-mode implementations.