Ring Oscillator

[ETRO_SSN583]

Why do neither of these oscillate ?

       

       

Regards, Dana.

[Bob_Marlowe]

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

       

Bob

[ETRO_SSN583]

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.

[EvPa_264126]

So Works, but questions still more...

[ETRO_SSN583]

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.

[ETRO_SSN583]

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.