[time-nuts] "Audio" DAC for GPSDO?

Bob Stewart bob at evoria.net
Mon Jun 2 17:02:20 EDT 2014


Now that my TIC is working with Bert's board, I'm considering taking the next step of designing a GPSDO from scratch.  There are several projects I'd like to do with a dsPIC33, so that was a natural choice.  But I now understand that it has an "audio" DAC and is not recommended for process control.  Could someone explain to me how such an audio DAC differs from a non-audio DAC and why it's not suitable for this application?  Is this just a disclaimer from microchip to avoid liability or is there some practical reason to go with a traditional DAC?  

On reading through the various datasheets, it appears to me that the concern might be that the input data to the DAC might be interrupted, thus causing it to go to some programmable "safe" output voltage.  My initial thought was just to control the value of the safe voltage and not bother to feed the DAC, though I haven't really explored the idea.

Bob - AE6RV


More information about the time-nuts mailing list