XC6SLX45-2FG484I Compared with XC6SLX45-3FGG484C

ElecSuppliers Part Number ComparisonAug 23, 2026

XC6SLX45-2FG484I and XC6SLX45-3FGG484C are two variants based on the XC6SLX45 Spartan-6 LX FPGA family. They share the same basic FPGA architecture and logic resources, but their speed grade, temperature grade and package designation need to be considered when selecting between them.

For engineers working on an existing FPGA design, the difference is important because a similar device name does not necessarily mean that two part numbers can be substituted without additional timing and hardware verification.

XC6SLX45-2FG484I vs XC6SLX45-3FGG484C

The most significant functional difference is the speed grade.

XC6SLX45-2FG484I uses a -2 speed grade, while XC6SLX45-3FGG484C uses a -3 speed grade.

The -3 speed grade provides higher performance than the -2 version. This can be important for designs with demanding internal timing, higher clock frequencies or limited timing margin.

However, the maximum performance of an FPGA design is not determined by the speed grade alone. Logic structure, routing, clock configuration and implementation constraints all affect the final achievable timing.

Temperature Grade Difference

The final letter in each part number also indicates an important difference.

XC6SLX45-2FG484I is an industrial-temperature version, while XC6SLX45-3FGG484C is a commercial-temperature version.

The industrial version is designed for a wider operating temperature range, making it more suitable for equipment exposed to demanding environmental conditions.

The commercial version is intended for applications operating within the commercial temperature range.

For industrial controllers, outdoor equipment and other products with wider environmental requirements, temperature grade should be considered before speed grade.

FPGA Logic Resources

Because both devices are based on XC6SLX45, their fundamental FPGA resources are closely related.

The XC6SLX45 family provides approximately 43,661 logic cells, 3,411 CLBs and 54,576 registers.

It also includes approximately 2.088 Mbit of block RAM and 58 DSP48A1 slices.

Therefore, the main reason to select one part over the other is not the amount of FPGA logic available. The more important considerations are speed grade, temperature rating and package compatibility.

XC6SLX45-2FG484I Performance

The -2 speed grade provides a lower performance level than the -3 grade.

For many control, industrial automation and general FPGA applications, this may still provide sufficient timing performance.

If the implemented design has comfortable timing margin, moving to the -2 device may not create a practical problem.

However, an FPGA design that already operates close to its timing limits should be evaluated carefully before moving from a -3 device to a -2 device.

XC6SLX45-3FGG484C Performance

The -3 speed grade is intended for applications requiring higher FPGA performance.

A faster speed grade can provide additional timing margin for high-speed internal logic and demanding data paths.

This can be useful in designs involving high-frequency processing, image-related logic, communication interfaces or other timing-sensitive functions.

The actual system performance still depends on the FPGA implementation, so the design should be re-evaluated after changing the speed grade.

Package Considerations

Both part numbers belong to the 484-ball BGA class, but the complete package designation should be checked before treating them as direct substitutes.

The package suffix is part of the full component specification.

For a new FPGA design, the selected package determines PCB footprint, routing requirements, assembly process and available I/O configuration.

For an existing PCB, the replacement device must be checked against the actual footprint and pin assignment before it is considered a drop-in alternative.

Can XC6SLX45-2FG484I Replace XC6SLX45-3FGG484C?

Not automatically.

The two devices have different speed grades and temperature grades, so replacing the -3 device with a -2 device requires timing verification.

If the original design depends on the additional performance provided by the -3 grade, the slower device may not meet the same timing constraints.

The industrial temperature rating of the -2I version can be an advantage in some applications, but this does not compensate for a timing failure.

For an existing design, the FPGA should be reimplemented and timing-checked using the proposed replacement before production.

Can XC6SLX45-3FGG484C Replace XC6SLX45-2FG484I?

The higher speed grade can provide additional performance, but the temperature grade creates an important limitation.

XC6SLX45-3FGG484C is a commercial-temperature device. If the original system requires an industrial-temperature FPGA, the commercial version may not be suitable.

The package and PCB footprint should also be verified.

Therefore, a higher speed grade does not automatically make the device a universal replacement.

Which XC6SLX45 Variant Should You Choose?

The choice depends on the requirements of the FPGA system.

XC6SLX45-2FG484I is more appropriate when industrial-temperature operation is important and the design does not require the higher performance of the -3 speed grade.

XC6SLX45-3FGG484C is more appropriate when the application operates within the commercial temperature range and FPGA timing performance is a higher priority.

For a new design, engineers should select the speed and temperature grade according to the actual operating environment and timing requirements rather than choosing the fastest available version by default.

XC6SLX45 Replacement Considerations

When looking for an XC6SLX45 replacement, the logic-cell count is only one part of the selection process.

The complete part number should be evaluated, including speed grade, temperature grade and package.

The FPGA design should also be checked for timing margin. A replacement with the same basic logic resources can still produce different timing results if its speed grade is different.

For production hardware, PCB footprint and assembly compatibility should be verified before making a component substitution.

XC6SLX45-2FG484I vs XC6SLX45-3FGG484C Summary

XC6SLX45-2FG484I and XC6SLX45-3FGG484C are closely related XC6SLX45 FPGA variants, but they are designed around different performance and operating-temperature requirements.

The -2I version emphasizes industrial-temperature operation, while the -3C version emphasizes higher FPGA speed within the commercial temperature range.

For replacement projects, timing verification and package compatibility are essential. For new designs, the best choice depends on the required FPGA performance, operating environment and PCB constraints.