You're right there are 3 phase detectors in the 4046: RS and JK flip-flops and and XOR gate.
On Wed, Jan 4, 2012 at 6:21 PM, Chris Albertson <albertson.ch...@gmail.com>wrote: > On Wed, Jan 4, 2012 at 12:58 AM, Hal Murray <hmur...@megapathdsl.net> > wrote: > > > > > Neat. Thanks for sharing. > > > > With a XOR, you can't tell which input is higher frequency. I think you > > can > > fix that with a second XOR and a delay line. > > > I think you can build a PFD or Phase Frequency Detector with three or four > flip flops. This avoid using the delay line and works over a wide range. > > If I'm not mistaken there is a PFD inside the 74HC4046. It uses flip > flops. Be sure to look at the 74HC type not the cd4046. The 75hc type > works up to 18MHz. > > > Chris Albertson > Redondo Beach, California > _______________________________________________ > 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. > _______________________________________________ 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.