Cluster Power Supplies

Since ZTEX FPGA Board communicate via USB it is easily possible to build low cost FPGA clusters using USB hubs. For this purpose typically USB-FPGA Modules 1.15x and USB-FPGA Modules 1.15d (if RAM is required) are used.

This article presents some suggestions for the power supply of such FPGA Board Clusters.

For small clusters 60W PSUs and 5-waqy DC splitter cables from the online shop can be used

• 12V/5A PSU
• 5-way DC spliiter cable

For larger FPGA clusters high efficient ATX PSU's with plugable cables are the best choice. The following guide explains how such a PSU can be modified for an FPGA cluster.

Requirements:

• ATX PSU
• power cables with 2.1/5.5mm plug for the FPGA boards, e.g. from http://search.digikey.com/scripts/DkSearch/dksus.dll?KeyWords=CP-2189-ND. Center pin wire (+12V) is marked with a white stripe
• bootlace ferrules and a crimp tool (e.g. from Ebay)
• luster terminal (e.g. from Ebay)
• heat shrink tubing (optional, e.g from Ebay)

Procedure:

1. Connect FPGA board power cables (the ones with the 2.1/5.5mm plug) to the cables from PSU. GND wires from PSU (black) should not power more than 3 FPGA Boards and +12V wires (yellow) should not power more than 5 FPGA Boards. (GND wires are more critical in order to reduce current flows through USB cable)
   1. Cut off the HD connector / GPU connector / ATX12V connector (i.e. not the to-PSU plug) from the PSU cable and cut FPGA power cables to the desired length.
   2. Strip off the insulation of the wire ends: