Hal Murray wrote: >> Every time I dig through the 5370 schematics, I think to myself >> "wouldn't it be nifty to build a replacement plug-in card with a >> modern fast CPU to run the instrument", but I try and stop myself >> there. >> > > Suppose you start with an FPGA on a PCI card. > > What sort of front end would you want? What can you build with home/hacker > technology? > > My straw man is something to turn a digital signal out of a comparator into a > ramp that gets feed into an A/D clocked on the system's internal clock. The > ramp needs to be a little over a cycle wide. > > Anybody got a circuit to make a linear ramp? > > Maybe the front half of the standard R/C exponential is good enough. Fixup > the non linearities in software. > > Somebody has mentioned a chip that does all this magic. I forget the number > but it's in the archives. I think it's European and maybe a touch pricey but > maybe not if it avoids the A/D and friends. > > Try
http://www.acam.de for time to digital converter chips. You could fit the entire replacement design on a relatively small single board. A pair of TDC chips plus an FPGA and a processor would be all that's required other than the input amplifiers and the IEEE 488 interface. However it would be necessary to use at least a 4 layer board with surface mount devices. Cost would way less than a new 5370 if they were still in production. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts