On Dec 12, 2007 2:32 AM, Bruce Griffiths <[EMAIL PROTECTED]> wrote: > Michael > > The analog circuitry for a sigma-delta DAC is attached. > The input is optically isolated using a high speed low jitter CMOS > optocoupler (Avago produce an equivalent device) to break low frequency > ground loops.
I was wondering if the Avago HCPL-9000 or Analog's ADUM1100 iCoupler would be suitable alternatives to the HCPL-7100. > Similarly an RF transformer should be used to couple the OCXO output to > the Digital board breaking another potential low frequency ground loop. For the RF transformer I am considering a Coilcraft WB1-6(S)L transformer to decouple the OCXO output. <http://www.coilcraft.com/wb_th.cfm> I want to do some more reading, but I think I'm might have some questions about DAC input data (from the microprocessor). Would there be any problems, or benefits to using AHC versus AC logic family flipflops and the inverting Schmitt triggers? In regards to the sawtooth correction, I am undecided. If I understand correctly, even without not addressing it there should be an improvement over existing public designs (Shera, Miller). If I remember correctly, you were keen on a software/firmware based sawtooth approach, if so that might be more flexible and cheaper than fiddling with a uncalibrated DS1020 delay line. Thank you, Michael _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.