Lattice GAL16V8B-15LD/883: A Comprehensive Technical Overview of the High-Reliability PLD
The Lattice GAL16V8B-15LD/883 represents a pinnacle of programmable logic design tailored for environments where failure is not an option. As a member of the iconic Generic Array Logic (GAL) family, this device combines architectural flexibility with the rigorous manufacturing and testing standards of MIL-PRF-38535 Class B (now often referred to as QML Class Q or V), making it a cornerstone for aerospace, military, and other high-reliability applications.
Architectural Foundation and Core Features
At its heart, the GAL16V8 is an electrically erasable programmable logic device (EE PLD). The GAL16V8B-15LD/883 variant specifically denotes a 15ns maximum propagation delay (tPD), a low-power standby mode, and a 20-pin ceramic leadless chip carrier (LD) package qualified for military temperature ranges (-55°C to +125°C).
The architecture is built around a programmable AND array feeding into fixed OR terms. A key innovation of the GAL family over its PAL predecessors is the use of Output Logic Macro Cells (OLMCs). These macro-cells provide unparalleled flexibility, allowing each of the eight output pins to be individually configured by the user as a dedicated input, a combinatorial output, or a registered output. This programmability eliminates the need for multiple fixed-function parts, simplifying board design and enhancing functionality.
The "883" suffix is critically important, signifying that the device is processed in accordance with MIL-PRF-38535. This entails:
Stringent Manufacturing Controls: Fabrication on a certified QML (Qualified Manufacturers List) line.
Rigorous Testing: Every device undergoes full electrical testing across the entire military temperature range.
Burn-in and Screening: Parts are subjected to burn-in and other accelerated stress tests to eliminate infant mortality and ensure long-term reliability.
Traceability: Full traceability of materials, processes, and test results for each lot.
Performance Specifications: The "-15" Designation
The -15 in the part number indicates a maximum propagation delay of 15 nanoseconds from any input to any output. This high speed, combined with a 100% functional test at the military temperature extremes, ensures reliable operation in the most demanding real-time control and signal processing systems. Furthermore, the CMOS-based E²CMOS technology offers a significant advantage in low power consumption, a critical factor in power-sensitive applications.
Application Domains
The combination of high speed, reprogrammability, and extreme reliability makes the GAL16V8B-15LD/883 ideal for a vast array of critical functions, including:
Address decoding and glue logic in avionics and military computing systems.
State machine implementation for system control.
Interface logic conversion (e.g., TTL to CMOS).
Bus interfacing and protocol management.
Its ability to consolidate multiple simple logic ICs (like 74-series parts) into a single, reliable package reduces board space, component count, and overall system weight while improving mean time between failures (MTBF).
Programming and Development
Development for the GAL16V8 follows a standard PLD workflow. Designers create logic designs using Hardware Description Languages (HDLs) like VHDL or Verilog, or more traditionally with schematic entry or Boolean equations. These are then compiled using PLD development software (e.g., Lattice's own tools or third-party suites) to generate a standard JEDEC file. This file is transferred to a high-reliancy PLD programmer capable of handling the specific electrical requirements of the QML device to configure the non-volatile E²CMOS cells.
ICGOODFIND: The Lattice GAL16V8B-15LD/883 remains a benchmark for high-reliability programmable logic. Its enduring relevance is a testament to a successful formula: a robust and flexible OLMC-based architecture, guaranteed high-speed performance (-15ns), and the unparalleled quality and reliability assurance of MIL-PRF-38535 (QML) screening. For engineers designing mission-critical systems where longevity, performance, and trust in components are paramount, this device continues to be an indispensable solution.
Keywords:
1. High-Reliability
2. Programmable Logic Device (PLD)
3. MIL-PRF-38535
4. Output Logic Macro Cell (OLMC)
5. Propagation Delay
