PALC16R4-35WC

Overview

The PALC16R4-35WC is a UV Erasable Programmable Logic Device (PLD) from the Cypress Semiconductor PAL®C20 family. It features 4 macrocells and utilizes a PAL-type architecture with CMOS technology. The device operates within a voltage range of 4.5V to 5.5V and supports a maximum clock frequency of 18 MHz. It offers a propagation delay of 35ns and includes 8 dedicated inputs with registered output functions. The component is housed in a 20-pin Ceramic Dual In-line Package (CDIP) with a windowed design, suitable for surface or through-hole mounting.

Feature Summary

• UV erasable programmable logic device utilizing PAL-type architecture
• Contains 4 macrocells with registered output functions
• Windowed ceramic package allows for optical erasure
• Supports high-speed logic operations up to 18 MHz

Applications

• Complex digital logic replacement in embedded systems
• State machine implementation for industrial control
• Address decoding and bus arbitration circuits
• Custom interface logic for legacy hardware integration

Procurement Notes

Verify the integrity of the quartz window on the ceramic package prior to installation, as physical damage may compromise UV erasability. Confirm that the specific suffix indicates RoHS compliance if environmental regulations apply. Ensure handling procedures protect the ceramic body from mechanical stress during insertion into sockets or PCB traces. Cross-reference the manufacturer part number against current availability status, as older PLD families may have limited supply chains.

Selection Notes

Select this component when a small number of macrocells are required for simple logic functions compared to more complex GALs or CPLDs. The UV erasability feature makes it suitable for prototyping and low-volume production where reprogramming is necessary. Consider the 20-pin CDIP footprint constraints and ensure the design accommodates the windowed package style. Verify voltage compatibility with the 4.5V to 5.5V operating range before integrating into the system.

Part Context

This part belongs to the Cypress Semiconductor PAL®C20 series of programmable logic devices. The series provides a cost-effective solution for replacing discrete logic gates in digital designs. The PALC16R4 variant specifically offers a balance between input/output capacity and internal complexity, serving as a foundational component for basic sequential and combinational logic applications in embedded environments.

Replacement Considerations

Direct pin-to-pin replacements may be limited due to the specific UV erasable nature of this component. Check for compatible parts within the same PAL®C20 family, such as the PALC16R8 series, which offers higher I/O counts but similar functionality. Ensure any substitute maintains the 35ns speed grade and CDIP20 package form factor for mechanical compatibility.