CMS82C55AZ

Overview

The CMS82C55AZ is a high-performance CMOS Programmable Peripheral Interface manufactured by Renesas Electronics Corporation. It serves as a static CMOS version of the industry-standard NMOS 8255A, utilizing an advanced SAJI process for low power consumption and high speed. The device provides 24 programmable I/O pins organized into three ports (A, B, and C), supporting multiple modes of operation including basic input/output, strobed input/output, and bidirectional bus handling. It operates on a single 5V supply with a voltage range of 4.5V to 5.5V. The component supports clock frequencies up to 8MHz without wait states and features TTL compatibility across commercial temperature ranges.

Feature Summary

• Static CMOS design ensures low operating power and eliminates the need for pull-up resistors through bus hold circuitry.
• Fully compatible with NMOS 8255A pinouts while offering enhanced performance and drive capability.
• Supports direct bit set/reset operations and enhanced control word read capabilities for flexible system integration.

Applications

• General-purpose parallel I/O expansion for 80C86 and 80C88 microprocessor systems.
• Industrial control interfaces requiring reliable TTL-compatible signal handling.
• Embedded systems needing bidirectional data bus management with minimal power consumption.

Procurement Notes

Verify the specific suffix 'Z' against the manufacturer's current datasheet to confirm RoHS compliance and lead-free status, as suffixes may indicate packaging or environmental variations. Confirm the active status and availability through authorized distributors, noting that some variants in the 82C55A family may have different moisture sensitivity levels or package dimensions. Ensure the ordering part number matches the required package type, such as PLCC-44, for your PCB layout.

Selection Notes

Select the CMS82C55AZ when a drop-in replacement for the NMOS 8255A is required with improved power efficiency and higher speed capabilities. This component is suitable for designs operating at 5V logic levels where static CMOS characteristics are beneficial. Consider the 44-pin PLCC package constraints and ensure the system clock does not exceed the specified maximum frequency for the specific speed grade. Verify thermal requirements if operating in enclosed industrial environments.

Part Context

The CMS82C55AZ belongs to the 82C55A family of programmable peripheral interfaces, which are widely used in legacy and modern embedded systems for parallel communication. Manufactured by Renesas (formerly Intersil), this component bridges the gap between older NMOS standards and modern CMOS requirements. It is often paired with other 80C/82C series components like the 82C59A interrupt controller or 82C54 timer to form complete system architectures.

Replacement Considerations

The CMS82C55AZ is functionally pin-compatible with the NMOS 8255A. Other CMOS equivalents from various manufacturers may also serve as replacements, provided they support the same voltage range and interface timing. Always verify electrical specifications and package dimensions before substituting.