Lattice GAL16V8D-20LD/883: A Comprehensive Technical Overview of the High-Reliability PLD
The Lattice GAL16V8D-20LD/883 represents a pinnacle of high-reliability programmable logic design, engineered specifically for demanding applications where failure is not an option. As a member of the iconic Generic Array Logic (GAL) family, this device combines proven architecture with stringent manufacturing and testing protocols to serve critical roles in aerospace, military, and industrial systems.
Architecture and Core Functionality
At its heart, the GAL16V8 is an electrically erasable programmable logic device (EE PLD). The GAL16V8D-20LD/883 variant features a 20-pin ceramic leadless chip carrier (LD/883) package, designed for superior thermal performance and reliability in harsh environments. Its core architecture consists of a programmable AND array feeding into a fixed OR array, with eight output logic macro cells (OLMCs). Each macro cell can be configured by the user for combinatorial or registered outputs, providing exceptional design flexibility. The "20" in its part number denotes a maximum propagation delay of 20 nanoseconds, ensuring high-speed operation for complex state machines and glue logic.
The Significance of the "/883" Suffix
The /883 suffix is the most critical differentiator. It signifies that the device is processed and tested in full compliance with the U.S. Department of Defense's MIL-PRF-38535 standard for integrated circuits. This entails:
Rigorous Testing: Undergoing full Class S or B electrical testing and burn-in screening to eliminate infant mortality failures.
Extended Temperature Range: Certified operation over the full military temperature range (-55°C to +125°C).
Stringent Quality Assurance: Manufactured on a certified QML (Qualified Manufacturers List) line, ensuring traceability and process control far exceeding commercial-grade parts.
Enhanced Longevity and Reliability: Designed and built to perform reliably for decades under extreme conditions of temperature, vibration, and radiation.
Key Features and Applications
The device's features make it indispensable for legacy systems and new high-reliability designs. Key attributes include:
High Reliability (Hi-Rel): Built for extreme environments.
Re-programmability: The EEPROM-based technology allows for design changes and field updates, a significant advantage over one-time programmable (OTP) parts.
100% Tested/QA: Every unit is subjected to exhaustive testing.
Pin-compatible Replacement: It often serves as a drop-in replacement for older bipolar PLDs (like PALs), reducing power consumption and improving reliability in existing system upgrades.
Its typical applications include:
Address decoding in avionics computers.
Interface glue logic in satellite subsystems.
State machine control in military-grade communications equipment.
System configuration and control logic in down-hole drilling and automotive systems.
Design and Programming
Despite being a mature technology, designing with the GAL16V8 remains relevant. Engineers use industry-standard hardware description languages (HDLs) like VHDL or Verilog, or simpler Boolean equations, to define the logic functions. These are then compiled into a JEDEC file using PLD development tools. A high-voltage programmer is required to electrically erase and program the device, with the security fuse able to protect the intellectual property contained within the design.
The Lattice GAL16V8D-20LD/883 is far more than a simple logic chip; it is a robust, certified solution for the world's most critical electronic systems. Its enduring presence underscores the value of proven, high-reliability technology in applications where performance and integrity must be guaranteed for the long term.
Keywords:
High-Reliability (Hi-Rel)
MIL-PRF-38535
Programmable Logic Device (PLD)
GAL16V8
Military Temperature Range
