DP8429D-70

Controllers Overview

The DP8429D-70 is a high-performance dynamic RAM controller manufactured by National Semiconductor. It supports data rates up to 70 MHz and manages DRAM refresh cycles, row/column addressing, and write protection. The device operates on a single +5V supply and features a 48-pin DIP package with MOS technology. It includes built-in logic for automatic refresh and self-timed writes, ensuring reliable memory system operation in commercial temperature ranges.

Controllers Feature Summary

• Supports high-speed dynamic RAM operations with integrated control logic
• Provides automatic refresh cycle management for connected memory banks
• Features self-timed write capability to simplify system timing requirements

Controllers Applications

• Personal computer memory subsystems
• Workstation main memory controllers
• Industrial control systems requiring fast DRAM access

Controllers Procurement Notes

Verify the specific suffix 'D-70' against official National Semiconductor or Texas Instruments documentation to confirm the 70 MHz speed grade and ceramic DIP package variant. Ensure compatibility with existing system timing constraints before procurement, as this component is an older generation part that may require careful integration into modern designs.

Controllers Selection Notes

Select this component when designing systems requiring a dedicated, high-speed DRAM controller with automatic refresh capabilities. It is suitable for applications needing robust memory management without complex external logic. Consider pin compatibility and voltage levels if replacing legacy designs, ensuring the 48-pin DIP form factor fits the target PCB layout.

Controllers Part Context

This part belongs to the DP84xx series of DRAM controllers from National Semiconductor, widely used in early PC architectures. It serves as a critical interface between the CPU bus and dynamic memory, handling the complex timing sequences required for DRAM stability. The series represents a standard solution for memory expansion in vintage computing hardware.

Controllers Replacement Considerations

Check for direct pin-compatible replacements within the DP84xx family. Verify if newer generations from Texas Instruments offer backward compatibility. Ensure any substitute maintains the same 70 MHz performance rating and 48-pin DIP configuration for mechanical fit.