AT49F002NT-90PI

Memory IC Overview

The AT49F002NT-90PI is a 5-volt only in-system reprogrammable Flash memory with a capacity of 2 megabits (256K x 8). It features a 90 ns access time and operates within a commercial temperature range of 0°C to 70°C. The device utilizes a 32-pin Plastic Dual Inline Package (PDIP) with a width of 0.600 inches. Electrical characteristics include an active current of 50 mA and a CMOS standby current of 300 µA.

Memory IC Feature Summary

• Sector architecture including a 16K byte boot block with programming lockout, two 8K byte parameter blocks, and two main memory blocks.
• Hardware data protection mechanisms such as VCC sense, program inhibit, and noise filtering.
• Internal program control and timer for sector or chip erase operations without external clocks.
• DATA polling and toggle bit features for end-of-program detection.

Memory IC Applications

• In-system reprogrammable code storage
• Secure boot code storage with lockout capabilities
• Parameter data storage

Memory IC Procurement Notes

Verify the package type matches the required 32-pin PDIP form factor. Confirm the operating temperature range aligns with commercial specifications. Ensure the voltage supply requirements match the 5V-only operation constraints. Check for any specific ordering suffixes that may affect pin configurations or electrical parameters.

Memory IC Selection Notes

Select this component when a 5-volt Flash memory with sector-based erasure and hardware data protection is required. Consider the 90 ns access speed and 32-pin DIP packaging for through-hole applications. Evaluate the need for boot block lockout features to secure critical system code against unintended modification.

Memory IC Part Context

This part belongs to the AT49F002 family of 2-megabit Flash memories manufactured by Atmel, now Microchip Technology. The family includes variants with different access times and packages, such as TSOP and PLCC. The 'N' indicates the presence of a RESET pin, while 'T' denotes the TSOP package option, though this specific model uses PDIP.

Memory IC Replacement Considerations

AT49F002NT-90PC

Memory IC FAQ

How is the boot block programming lockout feature enabled?

The feature is enabled by executing a specific six-command sequence involving loading data AA to address 5555, data 55 to address 2AAA, data 80 to address 5555, data AA to address 5555, data 55 to address 2AAA, and data 40 to address 5555.

What happens if the RESET pin is taken to 12 volts?

Applying 12 volts to the RESET pin overrides the boot block programming lockout, allowing the protected boot block data to be altered through chip erase, sector erase, or word programming.