P8255A-5

Specialized Overview

The P8255A-5 is a CMOS Programmable Peripheral Interface (PPI) manufactured by Rochester Electronics, LLC. It serves as a high-performance, static CMOS 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. Designed for compatibility with microprocessors such as the 80C86 and 80C88, it offers TTL-compatible logic levels and eliminates wait states during operation.

Specialized Feature Summary

• Static CMOS design ensures low power consumption and high-speed operation without requiring wait states.
• Pin-compatible with the legacy NMOS 8255A, facilitating direct upgrades in existing designs.
• Supports fully programmable I/O configurations with individual bit set/reset capabilities.
• Maintains TTL compatibility across the full military temperature range.

Specialized Applications

• Legacy system upgrades involving 8086/8088-based architectures
• Industrial control systems requiring reliable parallel I/O expansion
• Military and aerospace electronics utilizing wide temperature range components

Specialized Procurement Notes

Verify the specific manufacturing lot and date code against project requirements, as this component may be sourced from surplus or last-time-buy channels. Confirm that the package type matches the original PCB footprint. Ensure that the voltage levels and timing characteristics align with the host microprocessor interface before final integration.

Specialized Selection Notes

Select the P8255A-5 when a drop-in replacement for the NMOS 8255A is required with improved power efficiency. It is suitable for designs needing robust performance in harsh environments due to its military-grade temperature rating. Consider this part if the application demands static CMOS reliability while maintaining backward compatibility with standard 8255A software drivers.

Specialized Part Context

This component belongs to the 8255 family of programmable peripheral interfaces. It is functionally equivalent to the Intel 8255A but fabricated using advanced CMOS processes. Rochester Electronics provides this part to support the maintenance of legacy systems where newer CMOS variants like the 82C55A might not be available or where specific vintage specifications are mandated.

Specialized Replacement Considerations

The UPD8255AC-5 and 82C55A are functional equivalents. Verify pinout compatibility and electrical specifications, particularly supply voltage ranges and drive capabilities, before substituting.