AT28HC64B-90TU

Memory IC Overview

The AT28HC64B-90TU is a high-performance electrically-erasable and programmable read-only memory (EEPROM) manufactured by Microchip Technology. It provides 64K bits of nonvolatile storage organized as 8,192 words by 8 bits. The device features a 90 ns maximum access time and operates on a single 5 V ±10% power supply. It supports automatic page write operations for up to 64 bytes simultaneously. The component is housed in a 28-lead Plastic Thin Small Outline Package (TSOP).

Memory IC Feature Summary

• Supports automatic page write operations with internal address and data latches for up to 64 bytes.
• Includes hardware and software data protection mechanisms to prevent inadvertent writes.
• Features DATA Polling and Toggle Bit capabilities for efficient end-of-write cycle detection.
• Utilizes high-reliability CMOS technology ensuring extended endurance and long-term data retention.

Memory IC Applications

• Industrial control systems requiring reliable nonvolatile data storage.
• Embedded applications needing fast parallel EEPROM access.
• Systems utilizing Software Data Protection (SDP) for critical data integrity.

Memory IC Procurement Notes

Verify the specific ordering suffix TU corresponds to the 28-lead TSOP package configuration. Confirm that the industrial temperature range (-40°C to +85°C) aligns with your operational requirements. Ensure compatibility with the 5 V ±10% supply voltage specifications before finalizing procurement decisions.

Memory IC Selection Notes

Select this component when a 90 ns access speed is required alongside a compact TSOP footprint. Consider the AT28HC64B-70TU if faster performance is necessary, or the AT28HC64B-120TU for cost-sensitive applications where slower speeds are acceptable. Verify pinout compatibility with existing designs using SOIC or PLCC packages.

Memory IC Part Context

This part belongs to the AT28HC64B series of high-speed parallel EEPROMs. The series offers various access times and packaging options to suit different design constraints. The AT28HC64B family is designed for applications demanding robust data retention and flexible write protection features within a standard byte-wide interface.

Memory IC Replacement Considerations

AT28HC64B-70TU

Memory IC FAQ

How does the Software Data Protection (SDP) feature function?

SDP prevents inadvertent writes by requiring a specific three-byte command sequence to be written to designated addresses before any write operation can proceed. This state persists through power transitions until explicitly disabled.

What methods are available to detect the end of a write cycle?

The device supports DATA Polling, where reading the last written byte yields its complement during programming, and the Toggle Bit method, where I/O6 toggles between logic levels until the write completes.