The TMM41256C-15 is a 262,144-bit (256K x 1) Dynamic Random Access Memory (DRAM) chip manufactured by Toshiba Semiconductor and Storage. It's designed for applications requiring temporary data storage with moderate access speeds. The '-15' indicates an access time of 150ns.

Applications

• Computer Memory: Primarily used as main memory in older personal computers and workstations.
• Graphics Cards: Employed as video memory in early graphics card designs.
• Peripheral Devices: Found in printers and other peripherals as buffer memory.
• Instrumentation: Used in test equipment for temporary data storage.
• Industrial Control Systems: Utilized in industrial controllers and PLCs for data buffering.

Features

• Moderate Speed: 150ns access time enables adequate data retrieval and storage.
• High Density: 256Kbit storage capacity provides a substantial amount of memory in a single chip.
• Single 5V Power Supply: Operates on a single 5V power supply.
• Multiplexed Address Inputs: Reduces pin count through multiplexing row and column address inputs.
• TTL Compatibility: Compatible with standard TTL logic levels.
• Refresh Required: Requires periodic refreshing to retain data due to its dynamic nature.

Benefits

• Adequate Performance: 150ns access time provides sufficient speed for many applications.
• Compact Design: High density reduces board space requirements.
• Simplified Power Requirements: Single 5V power supply simplifies system power design.
• Easy Integration: TTL compatibility allows for easy interfacing with a variety of systems.
• Cost-Effective Solution: Provides a cost-effective solution for temporary memory storage.

Additional Details

The TMM41256C-15 typically comes in a 16-pin DIP (Dual In-line Package). It is a dynamic RAM, meaning it needs to be refreshed periodically (typically every few milliseconds) to maintain the stored data. Electrostatic discharge (ESD) precautions are essential when handling this device. For detailed electrical characteristics, timing diagrams, and refresh specifications, consult the official Toshiba datasheet. It utilizes multiplexed addressing to reduce the number of pins required. Its reliability and cost-effectiveness made it a popular choice for many applications in its era. Power supply decoupling is important for stable operation.