On Thu, Feb 2, 2012 at 12:21 PM, Tom Van Baak <[email protected]> wrote:
> I'm curious how a 10 MHz-driven high-end DDS would generate > 32 kHz with the lowest possible jitter? I wonder if your 32K diver could be improved if it used interpolation. In other words use an analog output. So at each cycle you decide what value to put out, either one or zero or some voltage between. The next question is why use a PIC divider? Why not a DDS? For low-end DDS the cost is not much different. Maybe $1 vs. $10 or about that. (don't say "10X" say "$9 more") The DDS does about the same thing is a PIC except that at each cycle it picks an entry from a sine wave table. I don't know if they interpolate or just use the nearest value. Your algorithm in the PIC, I think is the same as that but you use nearest value in your "square wave look up table". Try interpolating. and filtering. This can move to zero crossing to someplace unrelated to the 10MHz reference Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
