The XC3S50-5VQG100C is a low-cost, high-performance Field Programmable Gate Array (FPGA) from Xilinx’s Spartan-3 family, now under the AMD portfolio. Featuring 50,000 system gates, a compact 100-pin VTQFP package, and 1.2V core voltage, it is purpose-built for cost-sensitive, high-volume consumer and industrial electronic applications. Whether you are designing embedded control systems, digital signal processing circuits, or custom logic interfaces, the XC3S50-5VQG100C delivers proven programmable logic performance at an accessible price point.

---

What Is the XC3S50-5VQG100C?

The XC3S50-5VQG100C belongs to the Xilinx Spartan-3 FPGA family — one of the most widely adopted entry-level FPGA series in the programmable logic industry. The part number encodes its key attributes:

• XC3S50 — Spartan-3 series, 50K system gates
• -5 — Speed grade 5 (fastest in the Spartan-3 lineup), supporting up to 725 MHz internal clock
• VQG100 — 100-pin VTQFP (Very Thin Quad Flat Package)
• C — Commercial temperature range (0°C to +85°C)

As part of the broader Xilinx FPGA ecosystem, this device supports standard Xilinx design tools including the ISE Design Suite, making it straightforward to integrate into existing workflows.

Note: The XC3S50-5VQG100C is classified as obsolete / end-of-life by AMD/Xilinx and is no longer in active production. It remains available through authorized distributors and the secondary market for legacy design support and maintenance.

---

XC3S50-5VQG100C Key Specifications

General Overview Table

---

Electrical Characteristics Table

---

Package & Physical Dimensions Table

---

XC3S50-5VQG100C Architecture Deep Dive

Configurable Logic Blocks (CLBs)

The Spartan-3 architecture is built around 192 Configurable Logic Blocks, each containing four slices. Every slice includes two 4-input Look-Up Tables (LUTs), two flip-flops, and dedicated carry logic. This structure makes the XC3S50 effective for implementing state machines, counters, arithmetic operations, and custom combinational logic.

Block RAM and Distributed RAM

The device provides 72 Kb of dual-port Block RAM, organized as two 18 Kb blocks. This RAM is ideal for FIFOs, lookup tables, and local data storage within the FPGA. An additional 12 Kb of distributed RAM can be synthesized from unused LUT resources when the design requires it.

Digital Clock Managers (DCMs)

Two on-chip Digital Clock Managers provide flexible clock synthesis, phase shifting, and duty-cycle correction. DCMs allow designers to multiply or divide incoming clock frequencies and eliminate clock distribution skew — critical for synchronous digital designs.

Multiplier Blocks

Four dedicated 18×18-bit hardware multipliers are embedded in the silicon, enabling efficient DSP operations without consuming CLB resources. These are particularly useful in signal processing, motor control, and communication protocol applications.

I/O Standards Support

The XC3S50-5VQG100C I/O banks support a wide range of single-ended and differential I/O standards, including:

---

Speed Grade Explained: What Does “-5” Mean?

The -5 speed grade is the fastest variant in the XC3S50 lineup. A higher speed grade number in the Spartan-3 family indicates better timing performance:

Choosing the -5 grade is recommended when designs have tight setup/hold timing margins or require maximum operating frequency headroom.

---

Commercial vs. Industrial Temperature: Understanding the “C” Suffix

The trailing “C” in XC3S50-5VQG100C denotes the Commercial temperature range (0°C to +85°C). For applications requiring extended temperature operation, the industrial variant XC3S50-5VQG100I covers –40°C to +100°C.

---

XC3S50-5VQG100C Typical Application Areas

The XC3S50-5VQG100C is well-suited to a broad spectrum of embedded and digital design applications:

• Consumer Electronics — Remote controls, set-top boxes, portable devices
• Industrial Control — Motor controllers, sensor interfaces, PLCs
• Communications — UART, SPI, I²C, and custom protocol bridges
• Automotive (Commercial Grade) — Body electronics, infotainment peripherals
• Education & Prototyping — FPGA development boards, university labs
• Medical Devices — Low-complexity signal acquisition systems
• Test & Measurement — Custom logic analyzers, signal generators

---

Design Tools & Programming Support

The XC3S50-5VQG100C is supported by the following Xilinx/AMD development tools:

Configuration can be performed via JTAG, Master Serial, Slave Serial, SelectMAP, or from an external SPI/Flash device. The device supports both single-shot and persistent (PROM-based) configuration modes.

---

Ordering Information & Part Number Variants

The XC3S50 is available in multiple package and temperature configurations. The table below summarizes common variants:

---

XC3S50-5VQG100C vs. Competing Devices

The XC3S50-5VQG100C stands out in the 100-pin package category for its 725 MHz speed grade and tight integration of DCMs and hardware multipliers — features often absent in competing low-cost FPGAs at this gate density.

---

Frequently Asked Questions (FAQ)

Q: Is the XC3S50-5VQG100C still in production? The XC3S50-5VQG100C has been marked obsolete by AMD/Xilinx. It is no longer manufactured but remains available from authorized and independent distributors for legacy system support.

Q: What is a suitable replacement for the XC3S50-5VQG100C? AMD recommends evaluating the Spartan-7 (e.g., XC7S6, XC7S15) or Artix-7 series as modern replacements. These offer significantly higher performance and logic density in similar package footprints.

Q: Can I use Vivado to design for the XC3S50-5VQG100C? The Spartan-3 family is primarily supported by Xilinx ISE Design Suite. Vivado does not support Spartan-3 devices. ISE 14.7 is the last stable release that fully supports this device.

Q: What configuration memory is compatible with the XC3S50-5VQG100C? Compatible configuration PROMs include the XCF01S, XCF02S, and XCF04S from Xilinx, as well as standard SPI Flash devices depending on the configuration mode used.

Q: What does the “VQG100” package designation mean? “V” stands for Very Thin, “Q” for Quad Flat Pack, “G” indicates a lead-free (Green) version, and “100” is the pin count. The VTQFP package measures 14×14mm with a 0.5mm lead pitch.

---

Summary

The XC3S50-5VQG100C is a proven, entry-level FPGA from Xilinx’s Spartan-3 family, offering 50K system gates, 1,728 logic cells, 725 MHz operation, and 63 user I/O pins in a compact 100-pin VTQFP package. Optimized for cost-sensitive consumer and industrial applications, it provides dedicated block RAM, hardware multipliers, and digital clock managers that elevate it beyond simple glue-logic devices. While now obsolete, it continues to serve legacy designs and is an excellent choice for FPGA learning platforms and low-complexity embedded systems.

For the full range of programmable logic devices and design support, explore our complete Xilinx FPGA catalog.