The XC3S50-5TQ144C is a low-cost, high-performance field-programmable gate array (FPGA) from AMD Xilinx’s Spartan-3 family. Designed for cost-sensitive applications that demand programmable logic flexibility, this device delivers 50,000 system gates, a 144-pin TQFP package, and a commercial temperature rating — making it one of the most popular entry-level FPGAs in the industry.

Whether you are a hardware engineer prototyping a new design or sourcing components for a production run, the XC3S50-5TQ144C provides the right balance of logic capacity, I/O flexibility, and affordability. As part of the broader Xilinx FPGA product line, it benefits from decades of Xilinx design tools, IP cores, and community support.

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XC3S50-5TQ144C Key Specifications at a Glance

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What Does the Part Number XC3S50-5TQ144C Mean?

Understanding the part number helps engineers confirm they are ordering the correct variant:

The “C” suffix differentiates this from industrial (-I) or extended temperature variants. The -5 speed grade means it operates at moderate clock speeds — suitable for most general-purpose digital designs.

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XC3S50-5TQ144C Detailed Specifications

Logic and Fabric Resources

Memory Resources

Clock and Timing Resources

I/O and Interface

Power Supply Requirements

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Package Dimensions and PCB Footprint – TQ144

The XC3S50-5TQ144C uses a 144-pin Thin Quad Flat Package (TQFP), one of the most common surface-mount packages in professional PCB design.

The 0.5mm pin pitch requires careful PCB layout and a fine-pitch soldering process or reflow oven. Decoupling capacitors should be placed as close as possible to VCC_INT and VCC_AUX pins for stable operation.

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Spartan-3 Family Architecture Overview

The Spartan-3 is Xilinx’s third-generation low-cost FPGA platform, built on a 90nm process node. The XC3S50-5TQ144C is the smallest member of the Spartan-3 family, sitting at the entry point of the portfolio.

Spartan-3 Family Comparison

The XC3S50 is ideal for designs that do not require large logic capacity but benefit from FPGA reprogrammability and flexible I/O.

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Typical Applications for XC3S50-5TQ144C

The XC3S50-5TQ144C is used across a broad range of industries and application types:

Industrial and Embedded Applications

• Glue logic replacement: Replacing discrete logic ICs with a single programmable device
• Serial protocol bridges: UART, SPI, I²C bridging and protocol conversion
• Motor control sequencing: Simple state machines for stepper or DC motor controllers
• Sensor interface logic: Data acquisition front-ends for ADCs and sensors

Communications

• LVDS data links: High-speed differential data transmission between boards
• FIFO buffers and data alignment: Synchronizing data between clock domains
• Custom framing and packetization logic: Lightweight protocol implementations

Consumer Electronics and Education

• FPGA learning boards: Ideal for students learning HDL (VHDL or Verilog)
• Embedded controller peripherals: Offloading peripheral logic from microcontrollers
• Prototype and evaluation boards: Quick proof-of-concept for new digital designs

Automotive and Military (with appropriate screening)

• Signal conditioning: Pre-processing of sensor signals
• Safety interlocks and monitoring logic: Watchdog and supervisory circuits

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Configuration Modes for XC3S50-5TQ144C

The XC3S50-5TQ144C supports multiple configuration modes, allowing flexibility in system design:

For most standalone embedded applications, Master Serial mode with an external SPI flash (e.g., Xilinx XCF02S or compatible) is the most common approach.

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Design Tools and IP Support

Xilinx ISE Design Suite

The XC3S50-5TQ144C is supported by Xilinx ISE Design Suite (up to version 14.7, the final ISE release). This includes:

• ISE Project Navigator – HDL synthesis, simulation, and implementation
• CORE Generator – IP cores for memory interfaces, DSP, communications
• ChipScope Pro – In-circuit debugging and logic analysis
• iMPACT – JTAG-based device programming

Note: The Spartan-3 family is not supported by Vivado. Engineers must use ISE 14.7, which remains freely downloadable from the AMD/Xilinx website.

HDL Language Support

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XC3S50-5TQ144C vs XC3S50-4TQ144C vs XC3S50A: Speed Grade and Variant Comparison

The XC3S50-5TQG144C (note the “G”) is the Pb-free/RoHS-compliant version. The XC3S50-5TQ144C and XC3S50-5TQG144C are functionally equivalent and pin-compatible.

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Ordering Information and Part Variants

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PCB Design Guidelines for XC3S50-5TQ144C

Decoupling and Power Supply

• Place 100nF ceramic capacitors on every VCC_INT pin, as close as possible to the pad
• Place 100nF ceramic capacitors on every VCC_AUX and VCCO pin
• Add 10µF bulk capacitors per power rail near the device for low-frequency ripple suppression
• Use a 4-layer PCB minimum: signal, ground plane, power plane, signal

Signal Integrity

• Keep JTAG traces short and matched in length
• Use series termination resistors (22–33Ω) on high-speed output signals
• Route differential pairs (LVDS) with controlled impedance (100Ω differential)
• Avoid routing signals under the FPGA die area on inner layers

Thermal Considerations

• The XC3S50 has a low power envelope and does not require a heatsink in most applications
• Ensure adequate copper pour around the exposed paddle if using QFN variants (not applicable for TQ144)
• Operating junction temperature should be kept below 85°C for commercial-grade devices

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Frequently Asked Questions (FAQ)

Q: Is the XC3S50-5TQ144C still in production? A: The Spartan-3 family has reached end-of-life status with AMD Xilinx. However, significant inventory exists through authorized distributors and component brokers. Always verify stock availability before designing it into new products.

Q: Can I use Vivado with XC3S50-5TQ144C? A: No. Vivado does not support Spartan-3. You must use Xilinx ISE Design Suite version 14.7 or earlier.

Q: What is the difference between XC3S50-5TQ144C and XC3S50-5TQG144C? A: The “G” suffix denotes RoHS-compliant, lead-free solder terminals. Both parts are functionally and pin-identical.

Q: What configuration flash should I use with the XC3S50-5TQ144C? A: Common choices include the Xilinx XCF02S, Atmel AT45DB series, or standard SPI NOR flash chips compatible with Xilinx master serial configuration.

Q: What is the minimum VCC_INT voltage for the XC3S50? A: The core voltage (VCC_INT) is nominally 1.2V, with an operating range of 1.14V to 1.26V.

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Summary

The XC3S50-5TQ144C is a proven, widely adopted entry-level FPGA delivering 50,000 system gates, 97 user I/Os, dual DCMs, and block RAM in a compact 144-pin TQFP package. While based on mature 90nm technology, it remains a practical choice for legacy system maintenance, prototyping, education, and cost-sensitive applications where reprogrammable logic is required.

Its broad tool support under Xilinx ISE 14.7, extensive application examples, and affordable price point make it a reliable starting point for engineers new to FPGA design as well as seasoned professionals maintaining existing product lines.