Product Overview: XA3S50-4PQG208I FPGA Specifications

The XA3S50-4PQG208I is an automotive-qualified Field-Programmable Gate Array (FPGA) from AMD (formerly Xilinx), designed specifically for high-reliability applications requiring extended temperature ranges and enhanced durability. This industrial-grade programmable logic device belongs to the Spartan-3 family and delivers robust performance for cost-sensitive embedded systems in automotive, aerospace, and industrial control applications.

The XA3S50-4PQG208I features 50,000 system gates with 1,728 logic cells, making it an ideal solution for applications requiring moderate logic density with exceptional reliability. Built on 90nm CMOS technology, this FPGA operates at 1.2V core voltage and offers superior power efficiency while maintaining industrial-grade performance standards.

Technical Specifications and Key Features

Core Performance Characteristics

Package and Pin Configuration

Automotive and Industrial Temperature Ratings

Architecture and Memory Resources

Configurable Logic Block Details

The XA3S50-4PQG208I contains 192 Configurable Logic Blocks (CLBs), each featuring four slices. Every slice includes two logic function generators, carry logic, arithmetic logic gates, wide-function multiplexers, and two storage elements that can be configured as flip-flops or latches. This architecture provides flexible implementation of combinational and sequential logic functions.

Embedded Block RAM Configuration

Digital Clock Manager (DCM) Features

The integrated Digital Clock Manager provides advanced clock management capabilities including clock de-skew, frequency synthesis, phase shifting, and clock distribution. The XA3S50-4PQG208I includes two DCMs that support:

• Clock multiplication and division (from 1x to 32x)
• Phase shifting with fine-grain adjustment
• Duty cycle correction
• Clock distribution to global routing resources

I/O Standards and Interface Capabilities

Supported I/O Standards

The XA3S50-4PQG208I supports multiple I/O standards for flexible system integration:

SelectIO Technology Benefits

The SelectIO technology in the XA3S50-4PQG208I provides programmable I/O standards, allowing designers to interface with various logic families without external components. Features include:

• Individual pin-level programmability
• Input and output delay elements
• Programmable drive strength and slew rate
• Built-in pull-up and pull-down resistors
• Differential signaling support

Application Use Cases for XA3S50-4PQG208I

Automotive Electronics Applications

This automotive-grade Xilinx FPGA excels in demanding vehicle systems:

• Engine Control Units (ECUs) – Real-time control algorithms and sensor data processing
• Advanced Driver Assistance Systems (ADAS) – Camera interface processing and sensor fusion
• Body Control Modules – Lighting control, power management, and peripheral interfacing
• Infotainment Systems – Audio/video processing and display controllers
• Safety Critical Systems – ABS control, airbag deployment logic, and diagnostic interfaces

Industrial Control Systems

The extended temperature range makes this FPGA ideal for:

• PLC I/O Modules – Industrial protocol implementation and I/O expansion
• Motor Control – PWM generation and encoder feedback processing
• Process Automation – Sensor interfacing and control loop implementation
• Factory Automation – Communication protocol bridging and data acquisition
• Robotics Controllers – Motion control algorithms and real-time feedback

Aerospace and Defense Applications

• Avionics Systems – Flight control interfaces and data processing
• Communication Systems – Protocol conversion and signal processing
• Navigation Equipment – GPS receivers and inertial measurement interfaces
• Test Equipment – Data acquisition and signal generation

Programming and Development Tools

ISE Design Suite Compatibility

The XA3S50-4PQG208I is fully supported by the Xilinx ISE (Integrated Software Environment) Design Suite, providing comprehensive development tools:

HDL Support and IP Cores

• VHDL and Verilog – Full language support for design entry
• IP Core Library – Pre-verified functional blocks including DSP, memory controllers, and communication protocols
• Schematic Entry – Graphical design capture option
• Simulation Support – ModelSim, ISIM, and third-party simulator compatibility

Configuration and Programming Options

Configuration Memory Interfaces

Configuration Memory Requirements

• Bitstream Size: Approximately 439,264 bits
• Recommended Flash: 4Mbit SPI Flash or larger
• Configuration Time: Typically 5-10ms depending on interface
• Reconfiguration: Full dynamic reconfiguration support

Power Supply and Thermal Management

Power Supply Requirements

Typical Power Consumption

Thermal Considerations

• Thermal Resistance (θJA): Approximately 35°C/W with airflow
• Junction Temperature: -40°C to +125°C (automotive grade)
• Recommended Cooling: Natural convection or forced air for high-utilization designs
• Thermal Relief: Via stitching and thermal pads recommended in PCB design

Quality and Reliability Standards

Automotive Qualification

The “XA” prefix designates automotive-grade components meeting stringent quality requirements:

• AEC-Q100 Qualified – Automotive Electronics Council standards
• Grade 1 Temperature – -40°C to +125°C ambient operation
• Enhanced Screening – Extended burn-in and temperature cycling
• PPAP Compliant – Production Part Approval Process documentation available
• Zero Defect Manufacturing – Statistical process control and 100% testing

Reliability Metrics

Package and PCB Design Guidelines

PQFP-208 Footprint Requirements

When designing PCB layouts for the XA3S50-4PQG208I:

• Pad Dimensions: 0.28mm x 1.4mm typical
• Package Outline: 28mm x 28mm nominal body
• Pin 1 Indicator: Located at top-left corner
• Seating Plane Coplanarity: 0.08mm maximum
• Soldermask Clearance: 0.1mm recommended

PCB Layout Best Practices

Ordering Information and Part Number Decoding

Part Number Breakdown: XA3S50-4PQG208I

• XA = Automotive-grade extended temperature range
• 3S = Spartan-3 family designation
• 50 = 50,000 system gates
• -4 = Speed grade (enhanced performance)
• PQ = Plastic Quad Flat Pack package type
• G = RoHS-6 compliant, lead-free
• 208 = 208-pin package
• I = Industrial temperature range (-40°C to +100°C junction)

Available Variants and Alternatives

Comparison with Similar FPGAs

Spartan-3 Family Comparison

Competitive Alternatives

• Altera Cyclone III EP3C5: Similar gate count, lower cost, non-automotive
• Lattice MachXO2: Lower power, smaller footprint, integrated Flash
• Microsemi IGLOO: Enhanced radiation tolerance for aerospace
• Intel Cyclone IV: Higher performance, commercial temperature only

Design Migration and Upgrade Path

Migrating from Commercial to Automotive Grade

When transitioning from commercial Spartan-3 (XC3S) to automotive-grade (XA3S) variants:

1. Pin Compatibility – Direct drop-in replacement with identical pinout
2. Bitstream Compatibility – Same configuration bitstream across temperature grades
3. Electrical Specifications – Review VCCO and timing margins for temperature extremes
4. Documentation Updates – Update BOM and procurement specifications

Future-Proof Design Considerations

For designs requiring future scalability:

• Pin Migration – 208-pin package shared across XA3S50, XA3S200, XA3S400
• Resource Planning – Design with headroom for feature additions
• Tool Version Control – Maintain ISE project files for reproducibility
• IP Core Compatibility – Verify core licensing for device migration

Frequently Asked Questions

What is the difference between XC3S50 and XA3S50?

The XA3S50 is the automotive-qualified version featuring extended temperature range (-40°C to +125°C junction), enhanced reliability screening, AEC-Q100 qualification, and guaranteed operation in harsh automotive environments. The XC3S50 is the commercial grade with standard 0°C to +85°C operation.

Can I use the same development tools for automotive-grade FPGAs?

Yes, the Xilinx ISE Design Suite supports both commercial and automotive-grade Spartan-3 devices with identical design flows, synthesis, and implementation tools. The automotive qualification applies to the physical device, not the design software.

What configuration memory should I use with this FPGA?

For automotive applications, use qualified SPI Flash memory such as the Micron N25Q032A (4Mbit) or compatible devices rated for automotive temperature ranges. The configuration bitstream requires approximately 439Kbits, so 4Mbit or larger Flash is recommended.

Is the XA3S50-4PQG208I still in production?

While AMD (Xilinx) has introduced newer FPGA families, the Spartan-3 automotive series remains available for legacy designs and cost-sensitive applications. Contact authorized distributors for current availability and lead times, especially for automotive-qualified parts.

What PCB stackup is recommended for this FPGA?

A minimum 4-layer PCB is recommended with dedicated power planes for VCCINT (1.2V) and ground, with VCCAUX and VCCO distributed on internal layers. For high-speed applications or EMI-sensitive designs, 6-layer or 8-layer stackups provide better signal integrity.

Environmental and Compliance Information

RoHS and Environmental Compliance

Export Control Classification

• ECCN: EAR99 (for most destinations)
• HTS Code: 8542.33.0001
• Country of Origin: Various (check specific lot)
• Export Documentation: Available for automotive qualification packages

Technical Support and Additional Resources

Official Documentation

• Datasheet: DS099 – Spartan-3 Family Datasheet
• User Guide: UG331 – Spartan-3 Generation User Guide
• Packaging: UG112 – Spartan-3 Generation Packaging and Pinout
• PCB Design: UG338 – PCB Design and Layout Guide
• Automotive: DS681 – XA Automotive Spartan-3A FPGAs

Development Resources

• Reference Designs: Available through AMD website and community forums
• Application Notes: Over 50 application notes covering common implementations
• Training Materials: Free online courses for Spartan-3 architecture
• Community Support: Active forums and user groups for troubleshooting

Where to Purchase

The XA3S50-4PQG208I is available through authorized distributors including:

• Digi-Key Electronics – Worldwide distribution, small quantities
• Mouser Electronics – Global stock, rapid delivery
• Arrow Electronics – Volume pricing, automotive supply chain
• Avnet – Design support and fulfillment services
• Authorized AMD Distributors – Regional coverage and local support

Summary and Conclusion

The XA3S50-4PQG208I represents a proven, automotive-qualified FPGA solution for embedded systems requiring reliable programmable logic in harsh environments. With 50,000 system gates, 1,728 logic cells, and comprehensive I/O capabilities in a compact 208-pin PQFP package, this device strikes an optimal balance between functionality, cost, and reliability.

Key advantages include:

• Automotive-grade reliability with AEC-Q100 qualification
• Extended temperature operation from -40°C to +125°C
• Flexible I/O standards supporting multiple voltage levels and protocols
• Proven architecture with extensive design resources and community support
• Cost-effective solution for moderate-density programmable logic requirements

Whether you’re developing automotive control systems, industrial automation equipment, or aerospace applications, the XA3S50-4PQG208I delivers the performance, reliability, and flexibility required for mission-critical embedded designs. Its combination of automotive qualification, moderate logic density, and comprehensive development tool support makes it an excellent choice for new designs requiring long-term availability and proven reliability.

For detailed technical specifications, design support, and procurement information, consult authorized AMD distributors and refer to the official Spartan-3 documentation suite.