MD82C55/R

Specialized Overview

The MD82C55/R is a CMOS Programmable Peripheral Interface manufactured by Rochester Electronics. It serves as a high-performance, low-power version of the industry-standard NMOS 8255A. The device features 24 programmable I/O pins organized into three 8-bit ports (Port A, Port B, and Port C). It supports multiple operating modes including basic input/output, strobed input/output, and bidirectional bus handling. The component is designed for static operation, ensuring compatibility with microprocessors such as the 80C86 and 80C88 without requiring wait states.

Specialized Feature Summary

• CMOS technology providing low standby power consumption
• Pin-compatible with legacy NMOS 8255A devices
• Fully TTL compatible across the full military temperature range
• Supports direct bit set/reset capability on Port C

Specialized Applications

• General-purpose programmable I/O expansion in embedded systems
• Interface solutions for 80C86 and 80C88 microprocessor architectures
• Industrial control applications requiring robust I/O management

Specialized Procurement Notes

Verify the specific suffix 'R' against the manufacturer's official documentation to confirm package type and moisture sensitivity level. Ensure the source document explicitly identifies the part as an active or lifecycle-managed item from Rochester Electronics. Confirm RoHS compliance status if required by the target assembly process, as historical CMOS parts may vary in regulatory adherence.

Specialized Selection Notes

Select this component when a drop-in replacement for the NMOS 8255A is required with reduced power consumption. Verify that the system voltage aligns with standard 5V logic levels. Consider the PLCC-44 package dimensions if surface mount installation is necessary. Ensure the design accounts for the static nature of the CMOS interface to maintain signal integrity without pull-up resistors.

Specialized Part Context

This part belongs to the 82C55 family of programmable peripheral interfaces. Rochester Electronics typically sources and redistributes legacy components originally designed by manufacturers like Intersil or Harris. The MD82C55 variant specifically denotes the CMOS implementation, offering improved performance characteristics over the original bipolar versions while maintaining functional equivalence.

Specialized Replacement Considerations

The MD82C55/R is functionally equivalent to the Intel 82C55A and Harris HSP50016. Verify pinout compatibility before substitution. Other CMOS variants such as the IS82C55A or CS82C55A may serve as alternatives depending on package availability and specific manufacturing lot requirements.