AT28LV256-20JI

Memory IC Overview

The AT28LV256-20JI is a 256K (32K x 8) parallel EEPROM manufactured by Microchip Technology. It operates on a single 3.0V to 3.6V supply with a maximum access time of 200 ns. The device features 15 mA active current and 20 µA standby current. It supports page write operations for up to 64 bytes and includes hardware/software data protection. Available in PLCC-32, PDIP-28, SOIC-28, and TSOP-28 packages, it functions within an industrial temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Supports automatic page write operations for up to 64 bytes using internal address and data latches.
• Includes hardware and software data protection mechanisms to prevent inadvertent writes.
• Features DATA Polling and Toggle Bit methods for end-of-write cycle detection.
• Provides an extra 64 bytes of EEPROM memory for device identification or tracking.

Memory IC Applications

• Industrial control systems requiring nonvolatile storage
• Embedded applications needing low-voltage operation
• Data logging and configuration storage

Memory IC Procurement Notes

Verify the specific package type (PLCC, PDIP, SOIC, or TSOP) required for your design, as the 'J' suffix indicates PLCC-32. Confirm that the system power supply strictly adheres to the 3.0V to 3.6V operating range. Ensure compatibility with the industrial temperature grade (-40°C to +85°C). Check for any export restrictions or additional documentation requirements associated with this component.

Memory IC Selection Notes

Select this component when a 256K capacity is needed with low-voltage 3.3V operation. The 200 ns speed is suitable for most asynchronous microcontroller interfaces. Consider the PLCC-32 package if through-hole mounting is not required but surface mount density is moderate. Verify that the system can handle the 15 mA active current consumption during read/write cycles.

Memory IC Part Context

This part belongs to the AT28LV256 series of low-voltage EEPROMs. It shares architectural similarities with other 256K devices in the family but is distinguished by its 3.0V-3.6V supply requirement and 200 ns access time. The 'JI' suffix specifically denotes the Industrial temperature range and PLCC-32 package.

Memory IC Replacement Considerations

AT28LV256-20JC (Commercial Temp)

Memory IC FAQ

How is the end of a write cycle detected?

The end of a write cycle can be detected via DATA Polling, where I/O7 outputs the complement of the written data until completion, or by monitoring the Toggle Bit on I/O6, which stops toggling when the write finishes.

What is the purpose of the extra 64 bytes of memory?

The additional 64 bytes are available for device identification or tracking purposes. They are accessed by raising A9 to 12V ± 0.5V and using address locations 7FC0H to 7FFFH.