GAL20V8-25QVC

Programmable Logic Device Pld Overview

The GAL20V8-25QVC is an Electrically Erasable Programmable Logic Device (EE PLD) manufactured by National Semiconductor. It features a PAL-type architecture with 20 input lines, 8 I/O lines, and 8 output lines. The device operates with a maximum propagation delay of 25 ns and supports a maximum clock frequency of 37 MHz. It utilizes a 28-pin Plastic Quad Chip Carrier (PQCC28) package. Key internal structures include 8 macrocells, shared input/clock capabilities, and register preload functionality. The component is designed for high-speed logic applications requiring reprogrammability.

Programmable Logic Device Pld Feature Summary

• PAL-type EE PLD architecture with 64 product terms
• 25 ns propagation delay and 37 MHz maximum clock frequency
• 20 dedicated inputs, 8 I/O lines, and 8 outputs in a 28-pin PQCC package
• Includes 8 macrocells with shared input/clock and register preload

Programmable Logic Device Pld Applications

• High-speed digital logic replacement for standard TTL/CMOS gates
• State machine implementation in embedded systems
• Address decoding and bus control logic
• Timing generation and synchronization circuits

Programmable Logic Device Pld Procurement Notes

Verify the manufacturer origin as National Semiconductor, noting that Texas Instruments acquired its semiconductor assets. Confirm the specific suffix 'QVC' corresponds to the plastic LCC-28 package and commercial temperature range. Check RoHS compliance status, as older revisions may not meet current environmental standards. Ensure the source provides valid lot traceability for quality assurance purposes.

Programmable Logic Device Pld Selection Notes

Select this component when a 25 ns speed grade is required for PAL-compatible logic functions. Compare against GAL20V8-15 variants if faster switching speeds are necessary. Verify pin compatibility with existing PCB layouts using the 28-pin QCCJ footprint. Consider power consumption differences compared to CMOS-based CPLDs if low standby current is a critical design constraint.

Programmable Logic Device Pld Part Context

This part belongs to the GAL20V8 family of electrically erasable programmable logic devices. It serves as a direct upgrade path from mask-programmable PALs like the GAL20V8B, offering field-reprogrammability without changing the physical package or pinout. It bridges the gap between fixed logic gates and complex FPGA architectures.

Programmable Logic Device Pld Replacement Considerations

Direct pin-to-pin replacements include the Lattice GAL20V8A series and Atmel GAL20V8C series. Verify electrical parameters such as propagation delay and output drive strength to ensure functional equivalence. Confirm that the replacement device supports the same programming voltage and algorithm.