Meta Description: Buy XC3S50-4PQG208C – Xilinx Spartan-3 50K gate FPGA in 208-pin PQFP package. Speed grade -4, 3.3V I/O, 1.2V core. Full specs, pinout, and datasheet inside.
The XC3S50-4PQG208C is a field-programmable gate array (FPGA) from the Xilinx FPGA Spartan-3 family, manufactured by AMD (formerly Xilinx). Designed for cost-sensitive, high-volume applications, this device delivers a balance of logic density, I/O flexibility, and low power consumption — making it a popular choice for embedded systems, communications, and industrial control designs.
XC3S50-4PQG208C Overview
The XC3S50-4PQG208C belongs to the Spartan-3 series, Xilinx’s landmark low-cost FPGA platform. With 50,000 system gates, a commercial temperature rating, and a 208-pin Plastic Quad Flat Pack (PQFP) package, this device suits a wide range of logic implementation tasks. The “-4” speed grade and “C” commercial temperature suffix make it ideal for fast prototype development and production designs operating in standard environments.
XC3S50-4PQG208C Key Specifications
| Parameter |
Value |
| Manufacturer |
AMD (Xilinx) |
| Part Number |
XC3S50-4PQG208C |
| Series |
Spartan-3 |
| System Gates |
50,000 |
| Logic Cells |
1,728 |
| CLB Slices |
768 |
| Flip-Flops |
1,536 |
| Distributed RAM |
24 Kb |
| Block RAM |
72 Kb |
| Multipliers (18×18) |
4 |
| Digital Clock Managers (DCM) |
2 |
| Maximum User I/O |
124 |
| Package |
PQFP-208 (PQG208) |
| Speed Grade |
-4 |
| Core Voltage (VCCINT) |
1.2V |
| I/O Voltage (VCCIO) |
3.3V (multi-standard) |
| Temperature Range |
0°C to +85°C (Commercial) |
| Operating Frequency |
Up to ~200 MHz (depending on design) |
| RoHS Status |
RoHS Compliant |
XC3S50-4PQG208C Package Information
| Package Attribute |
Detail |
| Package Type |
Plastic Quad Flat Pack (PQFP) |
| Package Code |
PQG208 |
| Pin Count |
208 |
| Mounting Type |
Surface Mount Technology (SMT) |
| Package Dimensions |
28mm × 28mm (body) |
| Lead Pitch |
0.5mm |
| Lead Finish |
Tin (Sn) – RoHS compliant |
The 208-pin PQFP is a widely supported SMT package, compatible with standard PCB assembly processes and reflow soldering. Its fine 0.5mm pitch provides a high density of I/O in a compact footprint — an advantage over larger BGA packages when board space and inspection accessibility matter.
XC3S50-4PQG208C Logic Architecture
Configurable Logic Blocks (CLBs)
The Spartan-3 CLB architecture uses a matrix of 768 slices, each containing two 4-input Look-Up Tables (LUTs) and two flip-flops. This gives designers fine-grained control over logic implementation and resource utilization.
Block RAM
The XC3S50 integrates 72 Kb of on-chip Block RAM, organized as two 18 Kb true dual-port RAM blocks. These are suitable for FIFOs, lookup tables, data buffers, and small embedded memories.
Multiplier Blocks
Four dedicated 18×18-bit hardware multipliers accelerate DSP operations such as filtering, correlation, and arithmetic-intensive algorithms without consuming CLB resources.
Digital Clock Managers (DCMs)
Two integrated DCMs support clock synthesis, deskewing, phase shifting, and frequency division. Each DCM can eliminate clock distribution delays and generate multiple derived clock frequencies from a single source.
XC3S50-4PQG208C I/O Capabilities
| I/O Feature |
Detail |
| Max User I/O Pins |
124 |
| I/O Standards Supported |
LVCMOS, LVTTL, SSTL, HSTL, PCI, GTL+ |
| Differential Pair Support |
Yes (LVDS, RSDS, mini-LVDS) |
| On-chip Termination |
Pull-up, pull-down, keeper |
| Drive Strength |
2mA to 24mA (programmable) |
| Slew Rate Control |
Yes (Fast / Slow) |
The multi-standard I/O architecture allows each I/O bank to be independently powered, enabling seamless interfacing to 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic devices.
XC3S50-4PQG208C Configuration Options
The XC3S50 supports several configuration modes:
| Configuration Mode |
Description |
| Master Serial |
External serial PROM (e.g., XCF series) |
| Slave Serial |
Controlled by an external host |
| Master Parallel (SelectMAP) |
Fast 8-bit parallel configuration |
| Slave Parallel (SelectMAP) |
External processor-driven configuration |
| JTAG |
IEEE 1149.1 boundary scan and configuration |
| Slave SPI |
Via external SPI Flash |
Configuration bitstream size for the XC3S50 is approximately 439 Kb.
XC3S50-4PQG208C Electrical Characteristics
| Electrical Parameter |
Min |
Typical |
Max |
| Core Supply (VCCINT) |
1.14V |
1.20V |
1.26V |
| I/O Supply (VCCIO) |
— |
3.3V |
— |
| Auxiliary Supply (VCCAUX) |
2.375V |
2.5V |
2.625V |
| Input Voltage (LVCMOS33) |
— |
— |
VCCIO + 0.5V |
| Static Current (ICCINTQ) |
— |
~5 mA |
— |
| Junction Temperature |
0°C |
— |
+85°C |
XC3S50-4PQG208C Speed Grade “-4” Explained
What Does Speed Grade -4 Mean?
In Xilinx Spartan-3 nomenclature, the speed grade (–4, –5) indicates the relative internal propagation delay performance. Speed grade –4 is the standard commercial-grade speed option, offering a balance of performance and cost:
- –4: Standard performance, suited for designs up to ~100–200 MHz.
- –5: Higher performance (faster), typically used in timing-critical designs.
For most embedded control, interface bridging, and protocol conversion applications, the -4 speed grade provides ample performance margin.
XC3S50-4PQG208C vs. Other Spartan-3 Devices
| Part Number |
Gates |
Slices |
Block RAM |
I/O |
Package |
| XC3S50-4PQG208C |
50K |
768 |
72 Kb |
124 |
PQFP-208 |
| XC3S200-4PQG208C |
200K |
1,920 |
216 Kb |
141 |
PQFP-208 |
| XC3S400-4PQG208C |
400K |
3,584 |
288 Kb |
141 |
PQFP-208 |
| XC3S50-4VQG100C |
50K |
768 |
72 Kb |
63 |
VQFP-100 |
| XC3S50AN-4TQG144C |
50K |
768 |
72 Kb |
97 |
TQFP-144 |
The XC3S50-4PQG208C offers the highest I/O count (124 pins) for the 50K gate density within the Spartan-3 family, making it the preferred choice when pin count matters more than logic density.
XC3S50-4PQG208C Typical Applications
The XC3S50-4PQG208C is widely used in:
- Industrial Control: Motor drive controllers, PLC I/O expansion, and sensor interfaces
- Communications: UART/SPI/I2C/JTAG protocol bridges and multi-protocol converters
- Consumer Electronics: Display controllers, keyboard/HID interfaces
- Test & Measurement: Signal capture, data logging front-ends
- Embedded Systems: Custom peripheral logic, glue logic replacement
- Automotive (non-AEC-Q100): Infotainment and body control logic prototyping
XC3S50-4PQG208C Design Tools & Support
| Tool |
Description |
| Xilinx ISE Design Suite |
Primary design, synthesis, and implementation tool for Spartan-3 |
| ISim |
Integrated simulation environment |
| ChipScope Pro |
In-system logic analysis (ILA, VIO cores) |
| iMPACT |
Device programming and configuration utility |
| CORE Generator |
IP core generation for DSP, memory, and interfaces |
| PlanAhead |
Floorplanning and timing analysis |
Note: Spartan-3 is supported by Xilinx ISE 14.7 (the final ISE release). Vivado does not support Spartan-3 devices. Designers working with legacy Spartan-3 projects should maintain an ISE 14.7 installation.
XC3S50-4PQG208C Ordering Information
| Field |
Detail |
| Full Part Number |
XC3S50-4PQG208C |
| Manufacturer |
AMD / Xilinx |
| DigiKey Part # |
122-1522-ND |
| Package |
208-PQFP |
| Lead-Free |
Yes |
| RoHS |
Compliant |
| Moisture Sensitivity Level (MSL) |
MSL 3 |
XC3S50-4PQG208C Part Number Decoder
Understanding the Spartan-3 part number format:
| Segment |
Value |
Meaning |
| XC |
XC |
Xilinx Commercial FPGA |
| 3S |
3S |
Spartan-3 family |
| 50 |
50 |
50,000 system gates |
| -4 |
-4 |
Speed grade (standard) |
| PQ |
PQ |
Plastic Quad Flat Pack (PQFP) |
| G |
G |
Green / lead-free package |
| 208 |
208 |
208 pins |
| C |
C |
Commercial temperature (0°C to +85°C) |
Frequently Asked Questions – XC3S50-4PQG208C
Q: Is the XC3S50-4PQG208C still in production? The XC3S50-4PQG208C is classified as a mature product by AMD/Xilinx. It remains available through authorized distributors, though designers starting new projects may wish to evaluate the Spartan-7 or Artix-7 families for long-term supply chain confidence.
Q: What programming tool do I need for the XC3S50-4PQG208C? You need Xilinx ISE 14.7 and the iMPACT utility, along with a compatible JTAG programming cable (e.g., Platform Cable USB II).
Q: Can the XC3S50-4PQG208C operate at 3.3V I/O? Yes. The I/O banks support 3.3V LVCMOS and LVTTL signaling natively. The core voltage (VCCINT) is 1.2V and must be supplied separately.
Q: What is the difference between XC3S50-4PQG208C and XC3S50-5PQG208C? The only difference is the speed grade. The -5 variant is faster (lower propagation delays), while the -4 is the standard performance option.
Q: Does the XC3S50-4PQG208C support DDR memory interfaces? Yes. Using the SSTL2/SSTL18 I/O standards and the DCM for clock alignment, it can interface with DDR SDRAM at low data rates. For higher-speed DDR2/DDR3 interfaces, a larger or newer FPGA family is recommended.
Summary
The XC3S50-4PQG208C is a proven, cost-effective FPGA solution for applications requiring moderate logic density, rich I/O, and standard-performance timing. Its 208-pin PQFP package with 124 user I/Os, integrated DCMs, Block RAM, and hardware multipliers make it a versatile choice for both prototyping and volume production in commercial-temperature environments. Backed by Xilinx’s ISE toolchain and a broad ecosystem of IP cores, this device remains a reliable platform for legacy and new designs alike.
