The XC3S1500-4FG676I 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 high-volume, logic-intensive applications, this device delivers 1.5 million system gates, 433 I/O pins, and industrial-grade reliability — all in a compact 676-ball Fine-pitch Ball Grid Array (FBGA) package. Whether you are designing embedded systems, digital signal processing applications, or communications hardware, the XC3S1500-4FG676I provides a proven, cost-effective Xilinx FPGA solution.
What Is the XC3S1500-4FG676I?
The XC3S1500-4FG676I belongs to Xilinx’s Spartan-3 generation, which was engineered specifically to reduce cost per logic cell while maintaining robust programmable logic features. The “4” in the part number denotes the speed grade (-4, the slowest in the Spartan-3 series), and the “I” suffix indicates industrial temperature range operation (–40°C to +100°C), making it suitable for harsh environments and extended-lifecycle industrial products.
XC3S1500-4FG676I Key Specifications
Core Logic & Architecture
| Parameter |
Value |
| Part Number |
XC3S1500-4FG676I |
| Manufacturer |
Xilinx (AMD) |
| FPGA Family |
Spartan-3 |
| System Gates |
1,500,000 (1.5M) |
| Logic Cells |
29,952 |
| CLB Slices |
13,312 |
| CLB Flip-Flops |
26,624 |
| Maximum Distributed RAM |
221,184 bits |
Memory Resources
| Memory Type |
Quantity / Capacity |
| Block RAM Tiles |
32 |
| Total Block RAM |
720 Kb |
| Distributed RAM |
221,184 bits |
I/O and Connectivity
| Parameter |
Value |
| Package |
FG676 (FBGA – Fine Ball Grid Array) |
| Total Ball Count |
676 |
| User I/O Pins |
487 |
| Differential I/O Pairs |
221 |
| I/O Standards Supported |
LVCMOS, LVTTL, SSTL, HSTL, LVDS, RSDS, PCI, GTL+ |
Performance & Power
| Parameter |
Value |
| Speed Grade |
-4 (standard) |
| Core Voltage (VCCINT) |
1.2V |
| I/O Voltage (VCCO) |
1.2V – 3.3V |
| Temperature Range |
–40°C to +100°C (Industrial) |
| Standby Current (ICCINTQ) |
~20 mA (typical) |
DSP & Clock Resources
| Parameter |
Value |
| Dedicated Multipliers (18×18) |
32 |
| Digital Clock Managers (DCMs) |
4 |
| Maximum Clock Frequency |
Up to 320 MHz (internal DCM) |
| Global Clock Networks |
24 |
XC3S1500-4FG676I Package Details
FG676 FBGA Package Overview
| Attribute |
Details |
| Package Type |
Fine-Pitch Ball Grid Array (FBGA) |
| Designation |
FG676 |
| Ball Count |
676 |
| Body Size |
27 × 27 mm |
| Ball Pitch |
1.00 mm |
| PCB Mount Type |
Surface Mount (SMD) |
| RoHS Status |
Lead-free options available |
The FG676 package offers a compact, high-density footprint that facilitates signal integrity and minimizes PCB board space — a critical advantage for complex, multi-layer PCB designs.
Spartan-3 Architecture: Inside the XC3S1500
Configurable Logic Blocks (CLBs)
The Spartan-3 CLB architecture consists of 4-input look-up tables (LUTs) arranged in slices. Each slice contains two LUTs, two flip-flops, and dedicated carry logic. The XC3S1500 features 13,312 slices (26,624 flip-flops), enabling complex sequential and combinational logic designs.
Block RAM
The device integrates 32 block RAM tiles, each providing 18 Kb of dual-port synchronous memory, totaling 576 Kb of true dual-port block RAM. This is ideal for FIFO buffers, look-up tables, and on-chip data storage in embedded designs.
Dedicated Multipliers
The XC3S1500 includes 32 dedicated 18×18-bit multipliers, enabling efficient hardware DSP pipelines for signal processing, filtering, and arithmetic-intensive applications without consuming CLB resources.
Digital Clock Managers (DCMs)
Four integrated Digital Clock Managers support clock multiplication, division, phase shifting, and deskewing. DCMs enable precise timing closure and eliminate clock distribution skew across the device.
XC3S1500-4FG676I Ordering & Part Number Decoder
Understanding the part number breakdown helps you select the right variant for your design:
| Field |
Code |
Meaning |
| Family |
XC3S |
Spartan-3 series |
| Gate Count |
1500 |
1.5 million system gates |
| Speed Grade |
-4 |
Slowest speed grade (standard timing) |
| Package |
FG676 |
676-ball FBGA, 27×27 mm |
| Temperature |
I |
Industrial (–40°C to +100°C) |
Available Speed Grades and Temperature Options
| Variant |
Speed Grade |
Temp Range |
Notes |
| XC3S1500-4FG676C |
-4 |
Commercial (0°C to +85°C) |
Lower cost |
| XC3S1500-4FG676I |
-4 |
Industrial (–40°C to +100°C) |
This product |
| XC3S1500-5FG676C |
-5 |
Commercial |
Faster timing |
| XC3S1500-5FG676I |
-5 |
Industrial |
Fastest + Industrial |
Applications for the XC3S1500-4FG676I
The XC3S1500-4FG676I is a versatile device used across a broad spectrum of industries and application domains:
Industrial & Embedded Systems
- Motor control and servo drives
- Industrial communication gateways (Profibus, CANbus, EtherCAT)
- PLC (Programmable Logic Controller) expansion
- Real-time data acquisition systems
Communications & Networking
- Multi-protocol bridging and switching
- Wireless baseband processing
- Protocol offload engines (SPI, I2C, UART, PCIe)
Consumer & Medical Electronics
- Digital video processing and scaling
- Medical imaging preprocessing (ultrasound, X-ray)
- Test and measurement instruments
Aerospace & Defense
- Radar and sonar signal processing
- Ruggedized embedded control systems (leverages the industrial –40°C to +100°C rating)
- Avionics data bus interfaces (ARINC 429, MIL-STD-1553)
XC3S1500-4FG676I vs. Similar Spartan-3 Devices
| Part Number |
Gates |
Logic Cells |
Block RAM |
I/O Pins |
Package |
| XC3S1500-4FG676I |
1.5M |
29,952 |
720 Kb |
487 |
FG676 |
| XC3S1000-4FG456I |
1.0M |
17,280 |
432 Kb |
333 |
FG456 |
| XC3S2000-4FG676I |
2.0M |
46,080 |
720 Kb |
489 |
FG676 |
| XC3S4000-4FG676I |
4.0M |
62,208 |
1,872 Kb |
489 |
FG676 |
| XC3S1500-4FT256I |
1.5M |
29,952 |
720 Kb |
190 |
FT256 |
The XC3S1500-4FG676I occupies a sweet spot in the Spartan-3 family — offering the maximum I/O count available in the FG676 package while remaining more cost-effective than the larger XC3S2000 and XC3S4000 devices.
Design & Development Tools
Xilinx ISE Design Suite
The XC3S1500-4FG676I is fully supported by Xilinx ISE Design Suite, which includes:
- ISE Project Navigator – RTL design entry and synthesis
- XST (Xilinx Synthesis Technology) – Automated logic synthesis
- PARTools (Place and Route) – Timing closure and physical implementation
- iMPACT – JTAG-based device programming and boundary scan
HDL Support
The device supports design entry in:
- VHDL
- Verilog
- Mixed-language designs
- Schematic entry (ISE)
Configuration Modes
| Mode |
Description |
| Master Serial |
From SPI Flash (most common) |
| Slave Serial |
Driven by external controller |
| Master Parallel (SelectMAP) |
Byte-wide parallel configuration |
| JTAG |
Direct boundary scan programming |
| Master SPI |
From dedicated SPI flash |
Electrical Characteristics Summary
| Parameter |
Min |
Typical |
Max |
Unit |
| Core Supply (VCCINT) |
1.14 |
1.20 |
1.26 |
V |
| I/O Supply (VCCO) |
1.14 |
— |
3.465 |
V |
| Operating Temperature |
–40 |
+25 |
+100 |
°C |
| Logic 0 Input Threshold (VIL) |
— |
— |
0.8 |
V |
| Logic 1 Input Threshold (VIH) |
2.0 |
— |
— |
V |
Why Choose the XC3S1500-4FG676I?
✔ Industrial-Grade Reliability
The “I” temperature suffix guarantees operation from –40°C to +100°C, making this FPGA suitable for outdoor systems, factory automation, and automotive-adjacent applications where commercial-grade parts fall short.
✔ High I/O Density
With 487 user I/O pins in a 27×27 mm footprint, the FG676 package provides exceptional pin density for complex PCB designs demanding numerous external interfaces.
✔ Proven Spartan-3 Ecosystem
The Spartan-3 family has an extensive installed base, deep documentation, proven IP cores (including Xilinx MicroBlaze soft processor), and a large community of engineers — reducing development risk.
✔ Cost-Effective 1.5M Gate Capacity
The XC3S1500 provides substantial programmable logic resources at a competitive price point versus higher-end 7-series or UltraScale devices, making it ideal for cost-sensitive, mature production designs.
Frequently Asked Questions (FAQ)
Q: What is the configuration memory size required for the XC3S1500-4FG676I? A: The XC3S1500 requires approximately 3,342,336 configuration bits, meaning you will need at least a 4 Mb (512 KB) SPI or parallel flash memory device.
Q: Is the XC3S1500-4FG676I RoHS compliant? A: Yes, lead-free (RoHS-compliant) versions are available. Confirm the specific RoHS code with your distributor at time of ordering.
Q: Can the XC3S1500-4FG676I implement a soft-core processor? A: Yes. The device can implement Xilinx’s MicroBlaze soft-core 32-bit RISC processor, as well as the smaller PicoBlaze 8-bit controller, using available CLB resources.
Q: What is the maximum user I/O voltage supported? A: The VCCO supply for I/O banks can range from 1.2V to 3.3V, supporting a wide variety of standard logic levels including 3.3V LVCMOS, 2.5V, 1.8V, and 1.5V.
Q: Is the XC3S1500-4FG676I pin-compatible with other Spartan-3 devices? A: Within the FG676 package, pin migration is supported between certain XC3S family members (e.g., XC3S1000, XC3S2000), facilitating design scalability. Consult the Xilinx Spartan-3 data sheet for the pinout migration table.
Summary
The XC3S1500-4FG676I is a mature, battle-tested FPGA that continues to serve in high-volume industrial, communications, and embedded applications worldwide. Its combination of 1.5 million system gates, 487 user I/Os, 32 block RAM tiles, 32 hardware multipliers, and an industrial temperature rating positions it as an excellent choice for designs that demand programmable logic density with long-term supply availability and an established design ecosystem.
For teams building new designs, Xilinx’s newer 7-series devices offer improved performance and lower power, but for production programs already designed around the Spartan-3 platform — or new cost-sensitive projects where the –4 speed grade is adequate — the XC3S1500-4FG676I remains a highly competitive and reliable component.
