24CW640T-E/ST66KVAO

Memory IC Overview

The Microchip Technology 24CW640T-E/ST66KVAO is a 64-Kbit (8 k x 8) serial EEPROM utilizing an I²C interface. It operates within a voltage range of 1.6V to 5.5V and supports clock frequencies up to 1 MHz. The device features software write protection via the Write Protection Register and programmable hardware client address bits. It offers high reliability with over one million erase/write cycles, data retention exceeding 200 years, and ESD protection greater than 4000V. The component is housed in an 8-lead TSSOP package and is qualified for extended temperature operation from -40°C to +125°C.

Memory IC Feature Summary

• Supports byte and page writes of up to 32 bytes within a single memory block.
• Includes programmable Configuration registers for software write protection and hardware address selection.
• Features output slope control to eliminate ground bounce and Schmitt trigger inputs for noise suppression.
• Provides low-power standby mode with current consumption as low as 1 µA at maximum voltage.

Memory IC Applications

• Automotive systems requiring AEC-Q100 qualification
• Industrial applications needing reliable nonvolatile storage
• Consumer electronics utilizing I²C bus architectures

Memory IC Procurement Notes

Verify the specific ordering suffix against official documentation to confirm package type, temperature grade, and tape-and-reel specifications. Ensure compatibility with system voltage requirements and I²C bus timing constraints before integration. Confirm RoHS compliance status through manufacturer datasheets or certificates of conformity.

Memory IC Selection Notes

Select this component for designs requiring 64-Kbit capacity with I²C connectivity. The Extended temperature grade (-40°C to +125°C) suits harsh environments. Verify that the 32-byte page size aligns with application write patterns to prevent data rollover across page boundaries. Ensure the host controller supports the required I²C protocol for proper addressing and acknowledgment handling.

Memory IC Part Context

This part belongs to the 24CW Series family of serial EEPROMs, which includes densities ranging from 16-Kbit to 128-Kbit. The series shares common electrical characteristics and interface protocols, differing primarily in memory organization and preset hardware client addresses defined by the base part number suffix.

Memory IC Replacement Considerations

Compatible substitutes include other 24CW64X variants with matching density and interface, such as the Industrial temperature grade version (e.g., 24CW640-I/ST). Verify pinout compatibility and ensure the replacement meets the required extended temperature range if operating conditions exceed industrial limits.

Memory IC FAQ

How does the device handle page write operations near memory boundaries?

If a page write attempts to cross a physical page boundary, the data wraps around to the beginning of the current page rather than proceeding to the next page. Application software must manage addresses to prevent unintended data overwrites.

What mechanism allows multiple devices to share the same I²C bus?

The Hardware Address Register (HAR) controls three hardware client address bits (A2, A1, A0), allowing up to eight devices with the same Device Type Identifier to be uniquely addressed on a common bus.