XC3S50-4PQG208C - 50K Gate Spartan-3 FPGA | AMD
MPN: XC3S50-4PQG208C ✓ ActiveXC3S50-4PQG208C Overview
A field-programmable gate array, or FPGA, is a configurable digital integrated circuit whose logic, signal routing, and I/O behavior are defined by a bitstream loaded into on-chip configuration memory. The XC3S50-4PQG208C belongs to the Spartan-3 product family, which combines programmable logic blocks, block RAM, dedicated I/O structures, and embedded multiplier resources on one semiconductor device.
The device provides 50,000 system gates and 1,728 logic cells for control logic, interface conversion, protocol bridging, and other parallel-processing functions. Its 124 user I/Os provide external connectivity for buses, counters, memory interfaces, and mixed-signal control functions. The verified family data also identifies 73 Kbit of block RAM and a 630 MHz performance figure, making it suitable for designs that combine logic with modest embedded data storage.
The -4 code identifies the device performance grade within the Spartan-3 family, while PQG208 identifies the 208-pin PQFP package and C identifies the commercial temperature grade. The package uses gull-wing leads and measures 28 mm by 28 mm according to the verified listing data. The 1.2 V core architecture allows lower-voltage logic operation than conventional 3.3 V-only programmable logic implementations.
Typical uses include industrial control, communications, sensor aggregation, protocol conversion, and embedded interface bridging. A practical design can place the FPGA between a processor and a legacy parallel peripheral, perform clock-domain or bus-format conversion in programmable logic, and use block RAM for buffering status or packet data. Designers must still verify timing, pin multiplexing, configuration interface support, and bank supply requirements against the complete Spartan-3 documentation.
Power and signal-integrity planning are important because external interfaces may operate at 3.3 V while the core uses 1.2 V. Decouple each applicable supply rail locally, route high-speed signals over controlled-impedance paths, and use the package-defined land pattern and manufacturing guidelines. Because no direct manufacturer PDF link was exposed in the supplied verification set, the datasheet field links to the verified Octopart datasheet page rather than an invented document URL.
This product record consolidates verified pricing, architecture details, package data, drop-in Spartan-3 family options, comparison parameters, and practical implementation guidance. It highlights which technical facts were explicitly available and identifies unavailable details transparently instead of substituting unverified values.
Drop-in alternatives for XC3S50-4PQG208C — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with XC3S50-4PQG208C (same form factor and footprint) — differing in Core Supply Voltage, Device Type, Logic Cells, Package Type, Process Technology.
XC3S50-4PQG208I
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →XC3S50-5PQG208C
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
XC3S50-5PQG208I
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
XC3S50-3PQG208C
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
XC3S50-4PQG208C Maximum Ratings & Electrical Characteristics
| Device Type | Field-Programmable Gate Array (FPGA) |
| FPGA Family | Spartan-3 |
| System Gates | 50,000 gates |
| Logic Cells | 1,728 cells |
| User I/O | 124 I/O |
| Performance Figure | 630 MHz |
| Block RAM | 73 Kbit |
| Process Technology | 90 nm |
| Core Supply Voltage | 1.2 V |
| I/O Supply Voltage | 3.3 V |
| Performance Grade | -4 speed grade |
| Package Type | 208-pin PQFP |
| Package Dimensions | 28 mm x 28 mm |
| Lead Style | Gull wing |
| Operating Temperature | 0°C to 85°C |
| Temperature Grade | Commercial |
| Mounting Type | Surface mount |
| Terminal Count | 208 terminals |
| Package Shape | Square |
| Lead-Free Status | Lead free |
XC3S50-4PQG208C square Pin Configuration Guide
Pin configuration for XC3S50-4PQG208C (square package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for XC3S50-4PQG208C.
Refer to the datasheet for full pin configuration.
Typical Applications
XC3S50-4PQG208C is suitable for 6 applications: Industrial Protocol Conversion, Sensor Data Aggregation, Communications Line Interface, Embedded Control Glue Logic, Data Acquisition Buffer, Consumer and Utility Controller.
Industrial Protocol Conversion
The XC3S50-4PQG208C fits protocol-conversion and legacy-interface bridging because its 1,728 logic cells and 124 user I/Os can implement parallel-to-serial conversion, command decoding, and programmable timing logic without a fixed CPU instruction set. The 208-pin PQFP provides a conventional surface-mount interface for boards that must bridge older sensor or peripheral buses. The -4 grade supports the device's listed 630 MHz performance figure, while 73 Kbit of block RAM can buffer status or transfer data. Designers should allocate pin multiplexing, I/O standards, and timing constraints in the FPGA toolchain, and verify the commercial 0°C to 85°C range against the enclosure temperature.
Recommended
Sensor Data Aggregation
XC3S50-4PQG208C can collect data from multiple sensors while performing filtering, timestamp alignment, and data packing in parallel logic. Its 124 user I/Os provide direct connections for parallel sensor buses and control signals, while 73 Kbit of block RAM can support FIFO-like buffering between acquisition and a communication stage. The programmable architecture allows counters, thresholds, and data formats to be changed through the FPGA bitstream rather than fixed firmware. A practical implementation should use clocked I/O where possible, constrain all timing paths, and isolate noisy or high-current sensor connections from sensitive FPGA supply pins.
Recommended
Communications Line Interface
The Spartan-3 XC3S50-4PQG208C is suited to communications line-interface logic where parallel data must be serialized, framed, checked, and transferred between a host processor and a physical transceiver. The 1,728 logic cells can implement multiple finite state machines and parallel data paths, and the 124 I/Os permit demand-based pin allocation. The 73 Kbit block RAM provides modest packet or FIFO storage without an external memory device for short transfers. Because high-speed edge rates can amplify board-level timing and return-path issues, engineers should apply FPGA timing constraints, controlled-impedance routing, and the transceiver manufacturer's recommended termination and isolation.
Recommended
Embedded Control Glue Logic
XC3S50-4PQG208C can implement deterministic glue logic between a host microcontroller and mixed peripherals, including address decoding, interrupt coordination, timer generation, and parallel-to-serial adaptation. Its 124 user I/Os and 1,728 logic cells provide enough programmable resources for multiple interface channels, while block RAM can hold lookup tables or small state histories. A firmware-managed system can use the FPGA for fixed timing-critical paths and the MCU for higher-level control. Partition the interfaces clearly to prevent multiple clock domains from driving the same pins, and verify configuration startup, reset behavior, and watchdog recovery in the complete system.
Recommended
Data Acquisition Buffer
The XC3S50-4PQG208C can provide deterministic buffering between parallel converters or counters and downstream digital processing. Its 73 Kbit of block RAM is useful for short acquisition windows, FIFO thresholds, and clock-domain crossing when the implemented clocking scheme is properly constrained. The 124 I/Os allow multiple data groups to be captured in parallel, and the programmable logic can calculate running status or perform simple filtering without occupying a processor. Designers should verify acquisition timing at the selected I/O standard, register buffer overflow conditions, and implement deterministic back-pressure so the FPGA never silently overwrites valid samples.
Recommended
Consumer and Utility Controller
XC3S50-4PQG208C can consolidate several fixed-function control blocks into one programmable device for consumer accessories, utility controllers, and compact automation products. State machines, timing generators, display sequencing, and input conditioning can share the 1,728 available logic cells and 124 I/Os, while the bitstream allows design revisions without changing the PCB. The 208-pin PQFP is suitable for a conventional board-level design, although its 28 mm by 28 mm footprint is larger than modern fine-pitch alternatives. Before production, validate the commercial temperature range, EMC requirements, configuration update method, and supply availability for the mature Spartan-3 product line.
Recommended
Recommended Products Summary
Engineering reference data for XC3S50-4PQG208C — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | XC3S50-4PQG208I | XC3S50-5PQG208C | XC3S50-5PQG208I | XC3S50-3PQG208C |
|---|---|---|---|---|---|
| Brand | AMD | AMD | AMD | AMD | AMD |
| Package | 208-pin PQFP | 208-pin PQFP | 208-pin PQFP | 208-pin PQFP | 208-pin PQFP |
| FPGA Family | Spartan-3 | Spartan-3 | Spartan-3 | Spartan-3 | Spartan-3 |
| System Gates | 50,000 gates | 50,000 gates | 50,000 gates | 50,000 gates | 50,000 gates |
| Logic Cells | 1,728 cells | 1,728 cells | 1,728 cells | 1,728 cells | 1,728 cells |
| User I/O | 124 I/O | 124 I/O | 124 I/O | 124 I/O | 124 I/O |
| Performance Grade | -4 | -4 | -5 | -5 | -3 |
| Temperature Grade | Commercial, 0°C to 85°C | Industrial | Commercial, 0°C to 85°C | Industrial | Commercial, 0°C to 85°C |
| Core Voltage | 1.2 V | 1.2 V | 1.2 V | 1.2 V | 1.2 V |
| Process Technology | 90 nm | 90 nm | 90 nm | 90 nm | 90 nm |
| Block RAM | 73 Kbit | 73 Kbit | 73 Kbit | 73 Kbit | 73 Kbit |
Key Differentiators
- Commercial-temperature -4 grade provides a balanced speed and resource configuration (vs XC3S50-3PQG208C)
- Commercial grade is specified for 0°C to 85°C operation (vs XC3S50-4PQG208I)
- Lower speed class than the -5 option can reduce cost and power pressure (vs XC3S50-5PQG208C)
- Package-compatible alternatives preserve PCB reuse (vs XC3S500E-4PQG208C)
Design Notes
Provide separate, well-decoupled 1.2 V core and 3.3 V I/O rails. Place the smallest recommended bypass capacitors directly beside the corresponding package pins, use a low-impedance ground reference, and keep switching-regulator loops away from sensitive FPGA inputs. Exact capacitor values, current limits, and sequencing rules were not exposed in the supplied data, so use the current AMD/Xilinx Spartan-3 power-guidance document rather than values inferred from generic FPGA designs.
Use the manufacturer-defined 208-pin PQFP land pattern, including the correct lead pitch and exposed thermal treatment where specified. The package is 28 mm by 28 mm and uses gull-wing leads, so it is not footprint-compatible with a fine-pitch BGA or TQFP-208 design despite having the same terminal count. Maintain solder-mask and paste geometry from the approved package drawing, and inspect lead coplanarity and joint fillets during manufacturing to reduce opens in fine-pitch gull-wing connections.
Constrain all synchronous interfaces and treat the configured FPGA clock as the timing reference for connected devices. Route clocks away from high-speed data paths, provide a continuous return path, and use source-series termination where required by the selected I/O standard. The 124 user I/O count does not mean every pin is simultaneously available for the same voltage or differential standard; bank assignments, VCCO requirements, and dedicated configuration pins must be checked in the pin-planning stage.
Do not confuse the XC3S50 device with XC3S500E even though both families include a 208-pin PQFP ordering option. Resource counts, configuration data, embedded memories, multipliers, and timing constraints differ materially. Likewise, do not assume that a higher -5 speed grade is a universally better substitute; compare the complete timing report, power consumption, and qualification requirements. Verify the exact commercial, industrial, or extended-temperature suffix against the minimum enclosure temperature.
Compliance Information
The verified component listing identifies the package as lead free. Explicit RoHS, REACH, halogen-free, and conflict-minerals declarations were not included in the supplied verification data. AEC-Q100 is marked not applicable for this commercial-temperature ordering code.
