The NEC D41257C-15 is a 262,144-bit (256K x 1) Dynamic RAM (DRAM) manufactured by NEC. It's a vital component in various memory-intensive applications that require fast data access and storage. As a DRAM, it utilizes capacitors to store each bit of data, necessitating periodic refresh cycles to maintain data integrity.

Applications

• Personal Computers: Used as main memory in older PCs.
• Graphics Cards: Employed in the frame buffer memory of early graphics cards.
• Printers: Integrated into printer memory for storing print data.
• Industrial Control Systems: Utilized in memory modules within industrial automation equipment.
• Embedded Systems: Suitable for embedded applications demanding low-cost memory solutions.

Features

• Capacity: 262,144 bits (256K x 1 organization).
• Access Time: 150ns access time.
• Refresh: Requires periodic refresh cycles to retain data.
• Power Consumption: Relatively low power consumption.
• Package: DIP (Dual In-line Package) for easy integration.
• Single 5V Supply: Operates on a single 5V power supply.

Benefits

• Cost-Effective: Provides a cost-effective memory solution for various applications.
• Wide Availability: Readily available from various distributors and suppliers.
• Easy Integration: Standard DIP package simplifies integration into existing systems.
• Established Technology: Mature DRAM technology ensures reliability and stability.
• Suitable for Legacy Systems: Ideal for maintaining and repairing older systems.

Additional Details

The D41257C-15 DRAM is a non-volatile memory component and loses its stored data when power is removed. Therefore, it is typically used in conjunction with other memory types, such as ROM or Flash memory, to store boot code or persistent data. The refresh cycle is critical for maintaining data integrity and must be implemented correctly in the memory controller. The specific refresh requirements (e.g., refresh interval, refresh mode) are detailed in the NEC datasheet for this part. The device uses multiplexed address inputs to reduce the pin count, requiring external address latches. This DRAM is sensitive to static electricity and should be handled with appropriate ESD precautions.

Note: The -15 suffix indicates the access time in nanoseconds. Faster versions of this DRAM may exist with different suffixes (e.g., -12, -10).