24LC21A-I/P

Memory IC Overview

The Microchip Technology 24LC21A-I/P is a 128 x 8-bit dual-mode Electrically Erasable PROM housed in an 8-pin PDIP package. It operates on a single supply voltage ranging from 2.5V to 5.5V and supports I2C-compatible 2-wire serial interfaces with clock frequencies up to 400 kHz at 5V and 100 kHz at 2.5V. The device features a self-timed write cycle, a page-write buffer for eight bytes, and ensures 1,000,000 erase/write cycles with data retention exceeding 200 years. Designed for industrial applications, it functions within a temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Implements DDC1/DDC2 interface standards for monitor identification with automatic recovery capabilities
• Supports dual operational modes: Transmit-Only for continuous memory streaming and Bidirectional for standard I2C read/write access
• Includes hardware write protection via the VCLK pin to prevent unintended array modifications
• Utilizes low-power CMOS technology with typical standby current consumption of 10 μA

Memory IC Applications

• Monitor identification and configuration storage
• Storage of control information requiring serial transmission
• Industrial systems needing non-volatile data retention

Memory IC Procurement Notes

Verify that the specific ordering suffix matches the required package type and temperature grade. Confirm RoHS compliance status if environmental regulations apply to your manufacturing process. Ensure the supplier provides official datasheets to validate electrical characteristics against your system requirements before finalizing procurement.

Memory IC Selection Notes

Select this component when dual-mode operation between DDC1 and I2C protocols is necessary for display or peripheral identification. Choose this part over standard EEPROMs if hardware write protection via VCLK is required. Verify that the operating voltage range aligns with your system's power supply rails and that the industrial temperature rating meets your environmental constraints.

Memory IC Part Context

This device belongs to the 24LC21A series of serial EEPROMs manufactured by Microchip Technology. It serves as a successor to the 24LC21, maintaining pin and function compatibility while adding dual-mode support. The series is designed for applications requiring reliable, low-power non-volatile memory with standardized serial communication interfaces.

Memory IC Replacement Considerations

The 24LC21 is a compatible predecessor with identical pinout and functionality but lacks the dual-mode DDC implementation.