CQ82C55AZ

Overview

The CQ82C55AZ is a CMOS Programmable Peripheral Interface (PPI) manufactured by Renesas Electronics Corporation. It provides 24 programmable I/O pins organized into three 8-bit ports, compatible with the industry-standard NMOS 8255A pinout. The device operates on a single 5V supply within a voltage range of 4.5V to 5.5V and supports clock frequencies up to 8MHz for wait-state-free operation with 80C86/80C88 processors. It features TTL compatibility, low standby power consumption, and direct bit set/reset capabilities. The component is housed in a 44-pin PLCC package and is designed for industrial temperature ranges.

Feature Summary

• Fully static CMOS design ensuring low power consumption and high-speed operation without wait states.
• Pin-compatible with the legacy NMOS 8255A, facilitating easy upgrades and system retention.
• Supports three major modes of operation with individual port programming flexibility.
• Includes bus hold circuitry to eliminate the need for external pull-up resistors.

Applications

• General-purpose I/O expansion for 8-bit and 16-bit microprocessor systems.
• Industrial control interfaces requiring robust TTL compatibility.
• Embedded systems utilizing 80C86 or 80C88 processor architectures.

Procurement Notes

Verify the specific suffix designation against official Renesas documentation to confirm temperature grade and packaging type. Confirm current production status as older CMOS variants may be subject to discontinuation notices. Ensure the ordering part number matches the required package style and environmental specifications for the target application.

Selection Notes

Select this component when a drop-in replacement for the 8255A is required with improved power efficiency. Consider the 44-pin PLCC package constraints for PCB layout. Verify that the system clock does not exceed the maximum rated frequency for the specific speed grade variant selected.

Part Context

The CQ82C55AZ belongs to the 82C55A family of programmable peripheral interfaces. This series represents the CMOS evolution of the classic 8255A, offering equivalent functionality with reduced power dissipation. It serves as a foundational interface chip for parallel data handling in legacy and modern embedded designs alike.

Replacement Considerations

The IQ82C55AZ and IS82C55AZ are functionally equivalent CMOS PPIs from the same manufacturer family. Verify package compatibility, as these alternatives may utilize MQFP or different PLCC variations. Cross-reference datasheets to ensure identical timing parameters and electrical characteristics before substitution.