The AT28HC64B-12JU: A High-Performance Parallel EEPROM for Demanding Systems

In the landscape of non-volatile memory, parallel EEPROMs have historically been the workhorses for systems requiring high-speed, random-access data storage. The AT28HC64B-12JU stands as a prime example of this robust technology, offering a reliable 64Kbit solution organized as 8,192 words by 8 bits. This device is engineered for applications where bus bandwidth and access time are critical performance metrics.

A defining characteristic of the AT28HC64B-12JU is its high-speed performance, as signified by the ‘-12’ suffix, which denotes a maximum access time of 120ns. This swift read capability allows microprocessors to fetch instructions and data with minimal wait states, significantly boosting the overall throughput of an embedded system. The parallel interface, featuring an 8-bit data bus and 13 address lines (A0-A12), provides a straightforward, memory-mapped connection to a system bus, enabling simple and efficient integration.

Beyond speed, this EEPROM incorporates several key features that enhance design flexibility and reliability. It supports a 5-volt ±10% single power supply, making it compatible with standard logic levels. The write cycle is self-timed and includes an automatic erase-before-write operation, simplifying the software driver development. Furthermore, the device offers both a software data protection mechanism and an optional hardware data protection scheme using the `WE` (Write Enable) and `CE` (Chip Enable) signals to prevent accidental data corruption. For even greater reliability, it features a page write mode, allowing 1 to 64 bytes of data to be written in a single cycle, which drastically reduces the total write time for block data operations.

The ‘JU’ package designation identifies it as a 32-lead Plastic J-Leaded Chip Carrier (PLCC), a compact and robust surface-mount package well-suited for automated assembly. Typical applications for the AT28HC64B-12JU are found in a wide array of demanding fields, including telecommunications hardware, networking equipment, industrial controllers, and sophisticated automotive electronics, where it is often used for storing configuration data, calibration constants, or program code.

ICGOODFIND: The AT28HC64B-12JU remains a compelling choice for designers of legacy systems or new designs where a parallel bus architecture is preferred. Its blend of high-speed access, robust data protection features, and a convenient page write mode ensures reliable and efficient non-volatile storage in performance-sensitive environments.

Keywords: Parallel EEPROM, High-Speed, Non-Volatile Memory, Page Write Mode, Data Protection