The AT28HC64B-70SU: A 70ns High-Speed 64K Parallel EEPROM from Microchip

In the realm of non-volatile memory, where the need for speed coexists with the requirement for data persistence, parallel EEPROMs have carved out a critical niche. The AT28HC64B-70SU from Microchip Technology (formerly Atmel) stands as a prime example of this powerful combination, offering a robust blend of high performance, reliability, and ease of integration for a wide array of sophisticated electronic systems.

This device is organized as 8K x 8 bits, providing a total of 64 kilobits of storage. Its defining characteristic is its impressive access time of 70 nanoseconds (max), signifying its position as a high-speed memory solution. This speed is crucial for applications where the processor cannot wait long cycles to fetch critical data or code, enabling systems to run at higher clock rates without being bottlenecked by memory latency.

A key feature of the AT28HC64B-70SU is its parallel interface. Unlike serial EEPROMs that transfer data one bit at a time, this device uses a full 8-bit data bus and 13 address pins, allowing an entire byte of data to be read or written in a single operation. This parallel access is fundamentally faster for bulk data transfers, making it ideal for shadowing BIOS code, storing configuration data for FPGAs, or serving as a fast, non-volatile code storage element in embedded systems that do not use external flash.

The device is designed for seamless integration into systems built around microprocessors and microcontrollers. It incorporates several user-friendly features that simplify design:

5V Single Power Supply Operation: Eliminates the need for additional voltage rails.

Compatible with JEDEC Standards: Ensures a familiar pinout and electrical characteristics.

Hardware and Software Data Protection: Sophisticated algorithms protect against inadvertent writes, securing data integrity.

High Endurance: Capable of > 10,000 write cycles per byte and a data retention period of over 10 years.

The `-70SU` suffix specifically denotes a 70ns speed grade and an SOIC (Small Outline Integrated Circuit) package, suitable for automated assembly processes and space-constrained PCB designs. Typical applications span across telecommunications hardware, advanced industrial controllers, high-end test and measurement equipment, and legacy computer system upgrades.

ICGOOODFIND: The Microchip AT28HC64B-70SU is a high-performance parallel EEPROM that masterfully balances blazing-fast 70ns access speeds with the inherent benefits of non-volatile storage. Its parallel architecture makes it a powerful solution for time-critical system initialization, fast code execution in place (XIP), and robust data storage in demanding embedded environments, bridging a vital gap between volatile RAM and slower serial memory.

Keywords: Parallel EEPROM, High-Speed Memory, 70ns Access Time, Non-Volatile Storage, Microchip Technology.