I'd rather design an open-source high-speed DAC silicon where you have control over all the transistors and can just make resistors exactly how you want them in silicon, instead of trying to deal with the unknown black box of driver stuff that's inside a digital I/O pins.
If someone will commit to buying a lot of.. I don't know, 10,000 DACs, then I can start working backwards from that and tell you how much they will cost and when you can expect to get them. What interface do you want on the digital side? I was thinking a Gigabit ethernet DAC would be a pretty cool toy. ;) On Sat, Nov 03, 2012 at 09:17:41PM +0000, Jack Carroll wrote: > To make a parallel DAC that's monotonic and doesn't have oversize steps at > the major bit carries, you need switches that introduce very small voltage > errors (less than 1/2 LSB worth of voltage at the MSB carry) or else errors > that are reproducible within 1/2 LSB from bit to bit. Generic output pins > from logic chips don't do that. I've done some designs of fast parallel DACs > with R/2R ladders and variant architectures, and getting the right switches > and a stable reference rail is the biggest challenge. Doing it at a high > update rate just makes everything tougher, and building it out of separate > switch chips and resistor arrays just makes everything harder, because the > physical size of the PCB interconnects between components adds stray > inductances and capacitances. If you can buy the DACs and line drivers, it's > a lot easier. > > Jack Carroll > > ----- Original Message ----- > From: "Timothy Normand Miller" <[email protected]> > To: "Ing. Daniel Rozsny??" <[email protected]> > Cc: [email protected] > Sent: Wednesday, October 31, 2012 9:48:35 AM > Subject: Re: [Open-graphics] The next OGA card? > > > > Actually, if we have lots of I/Os to spare, we might be able to do > analog video using a resistor network and a low-pass filter. Someone > with a better EE background could answer that. > _______________________________________________ > Open-graphics mailing list > [email protected] > http://lists.duskglow.com/mailman/listinfo/open-graphics > List service provided by Duskglow Consulting, LLC (www.duskglow.com) _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
