5 Replies Latest reply on Feb 24, 2013 2:49 PM by DaKn_263916

    Ring Oscillator


      Why do neither of these oscillate ?







      Regards, Dana.

        • 1. Re: Ring Oscillator

          Well, there is an optimizer which will start with thinking about what two NOTs can be replaced with...





          • 2. Re: Ring Oscillator

            Thanks Bob, once again I have to remember there is an extra


            agent in the room erasing my thoughts.




            Would be nice if each component had a property to "optimize or


            not optimize, that is the question", but then I could envision net


            synthesis times reaching into months.




            Regards, Dana.

            • 3. Re: Ring Oscillator

              So Works, but questions still more...

              • 4. Re: Ring Oscillator

                I did a 3 delay ring, basically got a pretty nice sinewave at 64 Mhz


                on a single pin. So PSOC is a RF generator, whoda thunk .....?


                Using 1 Ghz DSO for measurements. Lots of undershoot, ~ 1.2V,


                but no overshoot. -030 board.




                I plan on trying paralleling pins to see if that helps.




                I do see a number of questions in your capture, especially no phase


                difference between 2 outputs...........very low Fosc............




                Regards, Dana.

                • 5. Re: Ring Oscillator

                  I also did a XOR doubler off ring, actually got some output


                  at 124 Mhz, but only a volt pk-pk swing. Board and layout


                  would have contributed to this as well.




                  Normally on a wafer there is one or more ET test sites to help monitor


                  process. And as part of that test site is a ring oscillator to keep track


                  of what AC performance.




                  Regards, Dana.