Post
Topic
Board Hardware
Re: Avalon ASIC users thread
by
GenTarkin
on 27/08/2013, 15:16:14 UTC
What value resistor would I piggyback onto R10 to target 1.30V, or 1.25V?
For 1.3V (1.278V under load) I use 47k. No problem with 400MHz and 0.98% HW, Rejected 0.38%
For stability I suggest sold 2mm2 wire from coil to the end of board. Top cooper layer (VDD_1.2)  is too thin to carry such high currents.
Look on the picture below
https://www.dropbox.com/s/68f6k5tafw1i58f/20130825_025617-2.jpg



Im running with 31k piggyback and that gives me 1.336v under load at the bottom chip.

Be aware that for me at 460mhz I am 2x the wattage as a stock Avalon!   At bare MINIMUM you need a 1200watt powersupply for a 4 module unit!

I need to find out how to deal with 1600watt total at 460mhz!!!

Guy's,

I am wandering how you are able to get such higher rates? I am not hardware expert but according to my knowledge the TPS DC/DC converter can handle up to 20 Amps. At clocks higher that 400 maybe chip consumes 3-4A at 1.3V so 10 Chips *4A=40 Amps. Double the capacity that  TPS DC/DC can handle.

I would be more than happy if someone comments it
Thanks

According to the guys that have done the mentioned mods, thats a soft limit of the DC/DC converter. Meaning exactly what, I dont know =P ... I wonder if it has to do w/ hard limit of maximum POWER(watts) output as in maybe its max capable voltage @ 20amps is what its rated for. Which is a lot more than the voltage we put through it.