The XC3S50-4TQG144C is a field-programmable gate array (FPGA) from the Xilinx Spartan-3 family, now distributed under AMD. Built on proven 90nm process technology, this device delivers a practical balance of logic capacity, embedded memory, and configurable I/O in a compact 144-pin TQFP package. It is a cost-effective solution for embedded control, digital logic design, and interface bridging in space-constrained applications.

If you are evaluating Xilinx FPGA options for your next design, the XC3S50-4TQG144C is worth a close look for low-to-mid complexity projects that demand flexibility without high power overhead.

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What Is the XC3S50-4TQG144C?

The XC3S50-4TQG144C is a Spartan-3 series FPGA manufactured by Xilinx (AMD). The part number breaks down as follows:

• XC3S50 – Spartan-3 family, 50,000 system gates
• -4 – Speed grade 4
• TQG144 – 144-pin Thin Quad Flat Package (TQFP)
• C – Commercial temperature range (0°C to 85°C)

This device is suited for engineers who need programmable logic in a small footprint without requiring the resources of a high-density FPGA.

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XC3S50-4TQG144C Key Specifications

General Overview

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Electrical Characteristics

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Memory & Logic Resources

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Thermal & Environmental Ratings

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XC3S50-4TQG144C Pin Configuration

The 144-pin TQFP package provides up to 97 user-configurable I/O pins, with the remaining pins assigned to power (VCCINT, VCCO), ground, and configuration/programming signals. Key pin groups include:

• VCCINT pins – Internal core power (1.2V)
• VCCO pins – I/O bank supply voltage
• GND pins – Ground references
• User I/O (IOx_xx) – Configurable multi-standard I/O
• Configuration pins – CCLK, DIN, DONE, INIT_B, PROG_B
• JTAG pins – TDI, TDO, TMS, TCK for boundary scan and programming

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Spartan-3 Family: Where XC3S50 Fits

The Spartan-3 family ranges from 50K to 5M system gates. The XC3S50 is the entry-level member, making it ideal for:

The XC3S50-4TQG144C occupies the smallest gate-count position in the family, which translates to lower power consumption and lower cost — a strong fit for high-volume or battery-sensitive applications.

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Supported I/O Standards

One of the key strengths of the XC3S50-4TQG144C is its wide support for industry-standard I/O voltage levels:

This multi-standard flexibility makes it easy to interface with a wide variety of peripherals, processors, and memory devices in mixed-voltage systems.

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XC3S50-4TQG144C Applications

#### Embedded Control Systems

The XC3S50-4TQG144C is frequently used in microcontroller companion logic, where it handles glue logic, bus arbitration, and peripheral expansion without burdening the main processor.

#### Industrial Automation

In programmable logic controllers (PLCs) and motion control subsystems, this FPGA manages real-time I/O coordination, encoder interfacing, and state machine logic with deterministic timing.

#### Communications & Interface Bridging

The device supports UART, SPI, I²C, and parallel bus implementations in HDL, making it ideal for protocol conversion and interface bridging between legacy and modern digital systems.

#### Signal Processing

For moderate DSP tasks such as FIR filtering, PWM generation, and digital modulation, the on-chip LUTs and memory blocks provide sufficient resources without the overhead of a DSP-class FPGA.

#### Aerospace & Defense (Non-Radiation-Hardened)

The XC3S50-4TQG144C is used in support logic roles within controlled-environment subsystems where programmable flexibility is needed but radiation hardening is not required.

#### Education & Prototyping

Its low cost and manageable resource scale make it a popular choice for FPGA learning platforms, digital design coursework, and early-stage prototype validation.

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Configuration Methods

The XC3S50-4TQG144C supports multiple configuration modes to suit different system architectures:

Configuration data is typically stored in an external SPI Flash or parallel NOR Flash device. The FPGA loads its bitstream on power-up automatically when using a PROM.

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Development Tools & Software Support

The XC3S50-4TQG144C is fully supported by Xilinx design tools:

Note: Xilinx Vivado does not support Spartan-3 devices. ISE Design Suite (version 14.7) is the recommended and last-supported toolchain for the XC3S50-4TQG144C.

HDL support includes VHDL and Verilog, with simulation support via ModelSim and ISIM.

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Ordering & Part Status Information

Important: The Spartan-3 family has reached end-of-life status with Xilinx. Engineers starting new designs should evaluate migration to Spartan-6 (XC6SLX9) or Artix-7 family devices for long-term supply chain security.

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Comparable & Replacement Parts

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Frequently Asked Questions (FAQ)

Q: What does the “-4” speed grade mean in XC3S50-4TQG144C? Speed grade -4 defines the timing performance class of the device. In Spartan-3, a higher number indicates a faster device. Speed grade -4 supports maximum frequencies up to 630 MHz (internal logic), though real-world performance depends on the implemented design.

Q: Is the XC3S50-4TQG144C lead-free and RoHS compliant? Yes, the XC3S50-4TQG144C is available in a RoHS-compliant, lead-free package. Verify the exact compliance markings with your distributor at time of purchase.

Q: Can the XC3S50-4TQG144C run a soft-core processor? The 50K gate capacity is limited for full soft-processor implementations. The PicoBlaze™ 8-bit soft processor from Xilinx is well-suited for this device. MicroBlaze™ can be instantiated but will consume a significant portion of available resources.

Q: What is the TQFP-144 package footprint? The 144-pin Thin Quad Flat Package (TQFP) measures 20mm × 20mm with a lead pitch of 0.5mm. Standard SMD assembly processes apply.

Q: What configuration memory devices are compatible? Common choices include the Xilinx XCF01S (Platform Flash) or standard SPI/parallel NOR Flash devices. Refer to the Spartan-3 configuration application notes (XAPP452, XAPP453) for detailed interface guidance.

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Summary

The XC3S50-4TQG144C is a compact, cost-efficient Spartan-3 FPGA that provides 50,000 system gates, 1,728 logic cells, 73,728 bits of embedded memory, and up to 97 user I/Os in a 144-pin TQFP package. Operating at 1.2V core voltage and supporting a broad range of I/O standards, it is well-suited for embedded control, interface bridging, communications, and moderate signal processing tasks. While this part has reached end-of-life status, it remains available through authorized distributors for maintenance and legacy design support. New designs should consider migration to the Spartan-6 or Artix-7 families for long-term availability.