AT29C257-90JC

Memory IC Overview

The AT29C257-90JC is a 256K (32K x 8) 5-volt-only Flash memory in a 32-lead PLCC package. It features a 90 ns access time, 50 mA active current, and 300 μA standby current. The device supports page programming with internal latches for 64 bytes, hardware/software data protection, and DATA polling. Operating temperature range is 0°C to 70°C.

Memory IC Feature Summary

• Supports 5-volt-only reprogramming with single-cycle erase and program operations
• Includes internal address and data latches enabling 64-byte page programming
• Provides hardware and software data protection mechanisms against inadvertent writes
• Features DATA polling and toggle bit functionality for end-of-program detection

Memory IC Applications

• In-system programmable code storage
• Data storage requiring frequent updates
• Embedded systems needing nonvolatile memory
• Applications compatible with AT29C010A and AT29C512 pinouts

Memory IC Procurement Notes

Verify the specific suffix JC indicates the commercial temperature range of 0°C to 70°C and the 32J PLCC package. Confirm the manufacturer is Microchip Technology or Atmel as per historical records. Ensure the datasheet matches the 90 ns speed grade. Check for RoHS compliance status if required by your assembly process.

Memory IC Selection Notes

Select this component when a 256K capacity with 90 ns access is required. It is suitable for designs needing 5V operation only. Consider the PLCC package availability. Compare with AT29C257-70JC for faster access or AT29C257-90JI for industrial temperature ranges. Ensure system timing allows for the 10 ms page program cycle.

Memory IC Part Context

This part belongs to the AT29C series of 5-volt Flash memories. It is pin-compatible with AT29C010A and AT29C512, facilitating system upgrades. The device uses CMOS technology for low power consumption. It offers typical endurance of over 10,000 write/erase cycles.

Memory IC Replacement Considerations

AT29C257-70JC provides 70 ns access time in the same package. AT29C257-90JI offers the same electrical specs but for an industrial temperature range (-40°C to 85°C). Verify pin compatibility and voltage requirements before substitution.

Memory IC FAQ

How is the end of a program cycle detected?

The end of a program cycle can be detected using DATA polling on I/O7 or by monitoring the toggle bit on I/O6.

What is the page size for programming?

The device supports page programming of 64 bytes, utilizing internal address and data latches.

Does the device require high voltage for programming?

No, the AT29C257 requires only 5 volts for all reprogramming operations, including erase and program.