The XC3S400-4TQ144I is a high-performance, cost-optimized Field Programmable Gate Array (FPGA) from Xilinx (now AMD), part of the widely-adopted Spartan-3 family. Designed for volume-sensitive applications, the XC3S400-4TQ144I delivers 400,000 system gates in a compact 144-pin TQFP package with industrial-grade temperature tolerance. Whether you are designing embedded control systems, digital signal processing circuits, or communications interfaces, the XC3S400-4TQ144I offers an ideal balance of logic density, I/O flexibility, and low power consumption.

For engineers and procurement teams seeking reliable programmable logic solutions, explore our full range of Xilinx FPGA products to find the right device for your design.

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XC3S400-4TQ144I Key Specifications at a Glance

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What Is the XC3S400-4TQ144I? — Product Overview

The XC3S400-4TQ144I belongs to Xilinx’s Spartan-3 FPGA family, one of the most successful low-cost FPGA product lines ever released. The “400” in the part number denotes 400,000 equivalent system gates, while “4” refers to the -4 speed grade (the slowest/most power-efficient grade in the Spartan-3 lineup). The suffix “I” designates the industrial temperature range (–40°C to +100°C), making it suitable for demanding environments such as automotive electronics, industrial automation, and outdoor instrumentation.

The TQ144 package is a 144-pin Thin Quad Flat Pack (TQFP), offering a compact PCB footprint and ease of assembly with standard SMT processes.

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XC3S400-4TQ144I Architecture and Internal Resources

Configurable Logic Blocks (CLBs) and Slices

The XC3S400-4TQ144I contains 4,032 slices, arranged in a 56×72 array of CLBs. Each CLB consists of two slices, and each slice includes two 4-input Look-Up Tables (LUTs) and two flip-flops. This architecture supports efficient implementation of combinational and sequential logic, arithmetic functions, and state machines.

Embedded Block RAM

The device provides 16 block RAM tiles, each 18 Kb in size, totaling 288 Kb of true dual-port synchronous block memory. Block RAM can be configured in a variety of aspect ratios (up to 16K×1 or 512×36) and is ideal for FIFOs, lookup tables, frame buffers, and local data storage.

Dedicated Multipliers

Sixteen 18×18-bit dedicated hardware multipliers are embedded in the XC3S400-4TQ144I. These multipliers directly support DSP-style operations such as filtering, modulation, and mathematical transformations — all without consuming CLB resources.

Digital Clock Managers (DCMs)

Four on-chip Digital Clock Managers (DCMs) provide precise clock synthesis, phase shifting, frequency synthesis, and clock deskewing. DCMs allow designers to eliminate external clock buffers and achieve tight timing margins in high-frequency designs.

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XC3S400-4TQ144I I/O and Voltage Compatibility

I/O Pin Summary

Supported I/O Standards

The XC3S400-4TQ144I supports a wide range of single-ended and differential I/O standards, enabling seamless interfacing with common logic families and high-speed buses.

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XC3S400-4TQ144I Speed Grade and Timing Characteristics

The -4 speed grade is the slowest speed grade in the Spartan-3 family, offering reduced dynamic power consumption compared to -5 devices. It is well-suited for applications where logic density and power budget are prioritized over maximum operating frequency.

Note: Actual performance depends on device utilization, placement, routing, and operating conditions. Refer to the official Xilinx DS099 datasheet for guaranteed timing values.

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XC3S400-4TQ144I Package Information — TQ144 TQFP

The TQ144 is a 144-pin Thin Quad Flat Pack with a 0.5mm pin pitch and a 20mm × 20mm body. This surface-mount package is compatible with standard PCB reflow soldering processes and is widely supported by FPGA prototyping and production boards.

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Operating Conditions and Power Requirements

The XC3S400-4TQ144I’s 1.2V core supply reduces static and dynamic power consumption compared to older FPGA families, making it a strong choice for battery-operated or thermally constrained designs.

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XC3S400-4TQ144I Ordering and Part Number Decode

Understanding the Xilinx part number structure helps in identifying the exact device variant needed for procurement and BOM management.

The commercial temperature variant of this device is the XC3S400-4TQ144C (0°C to +85°C). For higher performance in the same package, consider the XC3S400-5TQ144I (-5 speed grade).

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XC3S400-4TQ144I vs. Other Spartan-3 Devices — Comparison Table

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Typical Applications for the XC3S400-4TQ144I

The XC3S400-4TQ144I is a versatile device used across a broad spectrum of industries and use cases. Its combination of gate density, block RAM, hardware multipliers, and industrial temperature range makes it especially well-suited for the following applications:

• Industrial Automation — Motor control, PLCs, sensor fusion, real-time data acquisition
• Communications — UART, SPI, I²C, Ethernet MAC controllers, protocol bridges
• Embedded Systems — Soft-core processor implementations (MicroBlaze, PicoBlaze)
• Digital Signal Processing (DSP) — FIR/IIR filters, FFT engines, audio processing
• Automotive Electronics — Robust industrial temperature range supports in-vehicle use
• Test & Measurement Equipment — Logic analyzers, pattern generators, data loggers
• Video and Image Processing — Pixel pipeline processing, timing controllers
• Prototyping and R&D — Low-cost platform for rapid algorithm evaluation

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Configuration and Development Tools

Configuration Modes

The XC3S400-4TQ144I supports multiple configuration modes to suit different system architectures:

Supported Development Tools

• Xilinx ISE Design Suite — Primary design environment for Spartan-3 (ISE 14.7 is the final recommended version)
• Xilinx ChipScope Pro — On-chip logic analyzer for debug
• ModelSim / ISIM — RTL simulation
• Xilinx iMPACT — JTAG programming utility
• Platform Cable USB II — Recommended JTAG programmer

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Why Choose the XC3S400-4TQ144I?

✅ Industrial Temperature Range

The “I” suffix guarantees reliable operation from –40°C to +100°C — critical for harsh industrial, automotive, and outdoor environments where commercial-grade devices may fail.

✅ Cost-Effective Logic Density

With 400K system gates and 8,064 logic cells, the XC3S400-4TQ144I delivers high logic density at a significantly lower cost per gate than higher-end FPGA families.

✅ Compact TQ144 Footprint

The 20mm × 20mm, 144-pin TQFP package minimizes PCB area while offering 97 user-configurable I/O pins with multi-standard support.

✅ Rich Memory and DSP Resources

288 Kb of block RAM and 16 hardware multipliers allow implementation of sophisticated DSP and memory-intensive algorithms without external components.

✅ Proven, Mature Ecosystem

The Spartan-3 family has been deployed in millions of production units worldwide. Extensive reference designs, IP cores, and community support are available through Xilinx and third-party sources.

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Frequently Asked Questions (FAQ)

Q: What is the difference between XC3S400-4TQ144I and XC3S400-4TQ144C? The only difference is the operating temperature range. The “I” suffix is Industrial (–40°C to +100°C), while the “C” suffix is Commercial (0°C to +85°C). All other specifications are identical.

Q: Is the XC3S400-4TQ144I still in production? The Spartan-3 family is considered mature/end-of-life by AMD Xilinx. Devices may still be available through authorized distributors and component brokers. For new designs, Xilinx recommends migrating to the Spartan-6 or Artix-7 families.

Q: What configuration memory is recommended for the XC3S400-4TQ144I? Xilinx recommends the XCF04S Platform Flash device (4 Mbit) for master serial configuration of the XC3S400.

Q: Can I run a soft-core processor on the XC3S400-4TQ144I? Yes. The PicoBlaze 8-bit soft-core processor from Xilinx runs efficiently on the XC3S400. The full MicroBlaze 32-bit processor can also be implemented but will consume significant logic resources.

Q: What JTAG cable is recommended for programming? Xilinx Platform Cable USB II (DLC10) is the recommended programmer for Spartan-3 devices.

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Related Part Numbers and Alternates

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All specifications are based on Xilinx DS099 Spartan-3 FPGA Family Data Sheet. Always verify with the official datasheet before finalizing your design.