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The XEM8350 requires a clean, filtered, DC supply within the range of 5 V to 18 V.  This supply must be delivered through the DC power connector.

The XEM8350 power distribution system is quite complex, with several supplies designed to provide suitable, efficient power for several systems and modules. A schematic diagram of the system follows, with input (+VDC) shown to the left and accessible supply rails shown to the right.

Supply Heat Dissipation (IMPORTANT!!)

Due to the limited area available on the small form-factor of the XEM8350 and the density of logic provided, heat dissipation may be a concern.  This depends entirely on the end application and cannot be predicted in advance by Opal Kelly.  Heat sinks may be required on any of the devices on the XEM8350.  Of primary focus should be the FPGA (U15) and SDRAM (U24, U25, U26, U27).  Although the switching supplies are high-efficiency, they are very compact and consume a small amount of PCB area for the current they can provide.

If you plan to put the XEM8350 in an enclosure, be sure to consider heat dissipation in your design.

Power Budget

The table below can help you determine your power budget for each supply rail on the XEM8350.  All values are highly dependent on the application, speed, usage, and so on.  Entries we have made are based on typical values presented in component datasheets or approximations based on Xilinx power estimator results.  Shaded boxes represent unconnected rails to a particular component.  Empty boxes represent data that the user must provide based on power estimates.

The user may also need to adjust parameters we have already estimated (such as FPGA Vcco values) where appropriate. All values are shown in milliwatts (mW). Note that this table does not include the two supplies dedicated to the GTX transceivers. These are independent and can be computed separately for power budget based on their assigned function.








200 MHz














FPGA Vccint, Vccbram







FPGA Vccaux







FPGA Vccaux_io







FPGA Vcco33,34 (DDR3), est.







FPGA Vcco14 (USB), est.














Total (mW)      
Available (mW)9,0004802,2502,70080019,800

Example XEM7360-K160T FPGA Power Consumption

XPower Estimator version 14.3 was used to compute the following power estimates for the Vccint supply. These are simply estimates; your design requirements may vary considerably. The numbers below indicate approximately 80% utilization.




Clock250 MHz GCLK, 163,237 fanout716 mW
Logic (DFF)250 MHz, 162,240 DFFs1,322 mW
Logic (LUT)250 MHz, 81,120927 mW
BRAM18-bit, 517 @ 250 MHz674 mW
DSP250 MHz, 480 slices605 mW
Memory Controller1600 Mb/s, DDR37 mW
GTXAurora, 8 lanes, 8 Gb/s458 mW
Misc.DCM, PLL, etc.5 mW
 Total4,714 mW
 Available6,000 mW

Heat Sink

The device has been fitted with two heat sink anchors, proximate to the FPGA for mounting a passive or active heat sink. The following heat sink has been tested with the XEM7360.

ManufacturerPart NumberDescription
Opal Kelly IncorporatedFANSINK-30X30-MCCustom with fan mount

The active heat sink above was custom built based on design specifications provided by Opal Kelly to mate to the XEM7360. It includes a small fan which connects to the fan controller on-board for manual or automatic fan speed control. It is available for purchase directly from Opal Kelly.

Heat Sink Dimensions


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