| MODEL P/N | SERIES | NUMBER OF LABS/CLBS | SPEED GRADE | NUMBER OF LOGIC ELEMENTS / CELLS | TOTAL RAM BITS | NUMBER OF I/O | VOLTAGE – SUPPLY | MOUNTING TYPE | OPERATING TEMPERATURE | PACKAGE / CASE | SUPPLIER DEVICE PACKAGE |
|---|---|---|---|---|---|---|---|---|---|---|---|
| XC4VLX25-11FFG668C | Virtex-4 SX | 2.688,00 | -11,00 | 24192 Logic Elements | 1,327,104 bits | 448 | 1.14 V ~ 1.26 V | Surface Mount | Commercial (0°C ~ +85°C) | 668‑BBGA, FCBGA | 668‑FCBGA (27×27) |
XC4VLX25-11FFG668C: High-Speed Virtex-4 LX Logic Platform
The XC4VLX25-11FFG668C is a high-performance FPGA within the Virtex-4 LX family, optimized for logic-heavy applications that demand tighter timing margins. Utilizing the 90nm process, the LX series focuses on maximizing logic-to-feature ratios, making it the preferred choice for high-speed I/O interfacing, frame buffering, and complex state machine implementations.
As a -11 speed grade device, this variant offers a performance boost over the standard -10, providing the necessary slack for designs running at higher clock frequencies or those with complex routing paths that are sensitive to propagation delays.
Core Technical Parameters
Logic Cells: 24,192
Max Clock Management Tiles (CMTs): 8 (Incorporating DCMs and PMCDs)
Block RAM: 1,296 Kb
DSP48 Slices: 48
Max User I/O: 448
Package: FFG668 (Fine-pitch Flip-Chip BGA, Pb-Free)
Speed Grade: -11 (High Performance)
Temperature Grade: Commercial ($0°C$ to $+85°C$)
Engineering Implementation & Design Notes
When integrating the XC4VLX25-11FFG668C into an existing system or a new legacy-support design, keep these hardware-level factors in mind:
Timing Closure: The -11 speed grade is approximately 10-15% faster than the -10. While this aids in meeting setup times ($T_{su}$), engineers should perform a secondary static timing analysis (STA) to ensure that hold time ($T_h$) violations haven’t been introduced in short paths due to the faster silicon.
Configuration Requirements: This device requires a 1.2V $V_{CCINT}$ supply. Ensure your power distribution network (PDN) is decoupled correctly with low-ESR capacitors near the FFG668 footprint to manage the transient currents typical of high-speed switching in the Virtex-4 architecture.
ISE Design Suite: Note that the Virtex-4 family is not supported by Vivado. You must use Xilinx ISE 14.7. If you are pulling an archived project, ensure your constraints file (.UCF) is mapped correctly to the 668-pinout to avoid I/O bank voltage conflicts.
Why Sourcing the -11 Grade Matters
In many medical and defense systems, the XC4VLX25-11FFG668C was specified because the design would not “lock” at the -10 speed grade. Replacing a -11 with a -10 can lead to intermittent system crashes or bit errors. We prioritize providing the exact speed grade specified in your original netlist to maintain system integrity.
Hardware Engineer’s FAQ
Can I use a -12 speed grade instead of this -11? Technically, yes. Xilinx speed grades are backward compatible; a faster part (-12) can always do the job of a slower part (-11), provided the thermal envelope remains within limits. However, the -11 is usually the “sweet spot” for cost vs. performance in maintenance cycles.
Does the FFG668 package require specialized soldering? The “FFG” signifies a Lead-Free Flip-Chip BGA. It requires a standard RoHS reflow profile. Because the die is mounted directly to the substrate (Flip-Chip), the package has excellent heat dissipation through the top of the chip, but it is sensitive to uneven mechanical pressure from heatsinks.
How do I handle the EOL (End of Life) status of this part? The Virtex-4 is a mature product. When sourcing, we recommend requesting the specific Date Code (D/C) and ensuring the parts have been stored in MSL-compliant (Moisture Sensitivity Level) packaging to prevent popcorn effects during reflow.
Contact LXB Semicon for availability, pricing, and technical support.
