MR82C84A/B

Overview

The Harris MR82C84A/B is a high-performance CMOS clock generator and driver designed for microprocessor systems. It supports both CMOS and NMOS architectures, including the 80C86, 80C88, 8086, and 8088 processors. The device integrates a crystal-controlled oscillator, a divide-by-three counter, and complete Ready synchronization and reset logic. It operates with an external frequency source from DC to 25 MHz and guarantees crystal-controlled operation up to 25 MHz using a parallel fundamental mode crystal. The component features TTL-compatible inputs over specified temperature and voltage ranges.

Feature Summary

• Integrates a crystal-controlled oscillator and divide-by-three counter for precise timing generation
• Provides complete Ready synchronization and reset logic for processor control
• Features static CMOS design for low power consumption compared to bipolar equivalents
• Maintains TTL compatibility for all inputs across operating temperature and voltage ranges

Applications

• Clock generation for Intel 80C86 and 80C88 microprocessors
• Timing circuits for legacy 8086 and 8088 based systems
• CMOS and NMOS microprocessor system synchronization

Procurement Notes

Verify the specific suffix designation (B) against the manufacturer's current datasheet to confirm exact electrical characteristics and package variations. Ensure the component meets the required industrial or commercial temperature range specifications for the target application environment before integration.

Selection Notes

Select this component when designing systems requiring a dedicated clock generator for 16-bit microprocessors. Consider the static CMOS architecture for applications prioritizing low power dissipation. Verify that the system design accommodates the necessary external load capacitors and parallel fundamental mode crystals for stable operation up to 25 MHz.

Part Context

This part belongs to the 82C84A family of clock generators produced by Harris Corporation, now part of Renesas Technology. The series was widely used in early personal computer architectures and embedded systems requiring reliable clock distribution and reset management for 8086-class processors.

Replacement Considerations

Check for direct pin-compatible replacements such as the Intersil 82C84A or compatible CMOS clock generators from other manufacturers. Ensure substitute components support the same 25 MHz maximum frequency and maintain TTL input compatibility for seamless integration into existing designs.